Home

HyperSQL User Guide - HyperSQL Database Engine (HSQLDB) 2.2

1. a ka 87 cal e n C 87 Authorizations and Access Control ssssssssssssessssseeee eene eene ee hne ee hh ee herein rre nennen 87 Built In Roles and gn 88 Lasting Wsersand Roles rte Ehe v t st ee dds ean Ge Siye dye ESE eee begs Sees 89 ACCESS RIBS MT 89 Statements for Authorization and Access Control esses ee eher eren 90 7 Data Access and Change sis cncenesenveqesssdossstecmenss ode tae pev estps e veros ue ert ul get etn pueevdt poe O E REE ae 95 iul 95 Cursors And Result Sets sesntcncassredcuse went nceamanum sete uhaseasvousune ne s Gi bere n ere NE UPS PROP RUSR EP DNE aiet 95 onu MC EET 95 INAVIB ALON e 95 liacirlobi dE 96 Sensitivity eee pasay suns 97 l 8 Ce L E10 115 AN Es 97 AVCOM dee a net kn et e MM 97 JDBC OVEFVISW METUIT 97 MID BC Parameters 2 anana pite avi ris kons at kepi E vo tate por UN w to kep e vye penn efe isk E eee UAE 98 JDBC and Data Change Statements 200 0 cece ee nce ce eee HH e meer 98 JDBC Callable Statement ci cete etre ee Seemnasvennnds e E E EOR E E E E 98 JDBC Returned Values 2 esce eter lie vr PE detekt eee Det UEM ee PAW ae del LORS ERE POPE EXT o teen 99 Cursor Declaration ote aran tele akt pe done a a ola eu nee epos da daki net tutup dre ewondePOU lab e eoru ko
2. Set the row clustering property of a table The column name list is a list of column names that must correspond to the columns of an existing PRIMARY KEY UNIQUE or FOREIGN KEY index or to the columns of a user defined index This statement is only valid for CACHED or TEXT tables Tables rows are stored in the database files as they are created sometimes at the end of the file sometimes in the middle of the file After a CHECKPOINT DEFRAG or SHUTDOWN COMPACT the rows are reordered according to the primary key of the table or if there is no primary key in no particular order When several consecutive rows of a table are retrieved during query execution it is more efficient to retrieve rows that are stored adjacent to one another After executing this command nothing changes until a CHECKPOINT DEFRAG or SHUTDOWN COMPACT or SHUTDOWN SCRIPT is performed After these operations the rows are stored in the specified clustered order The property is stored in the database and applies to all future reordering of rows Note that if extensive inserts or updates are performed on the tables the rows will get out of order until the next reordering SET TABLE TYPE set table type set table type statement SET TABLE table name TYPE MEMORY CACHED Changes the storage type of an existing table between CACHED and MEMORY types Only a user with the DBA role can execute this statement SET TABL
3. HI E Apply Revert Filter matched 7 of 7 item 9 Run Close i Configuring Gradle GUI Launcher in Eclipse Depending on your Eclipse version and workspace setup the value populated into the Location field after you select the program may appear very differently than in this screen shot 6 Click the Run button The Gradle Gui should run If you just Apply and Close here instead of Run the new Gradle launch item will not be added to the pulldown and toolbar menus After doing the Eclipse setup you can use pulldown menu Run External Tools or the equivalent tool bar button button to launch the Gradle Gui 284 HyperSQL Building HyperSQL Jars sw Java Eclipse home blainelespace31 16 W c e File Edit Navigate Search Project Run Window Help a e 0 a 3 8 oe ot Ei 2 hsqldb 16 build xml hsqldb 3k 3 hsqldb 1 4 build xml hsqldb 3t 4 hsqldb 1 4 build xml switchtojdk1 4 Run As P i autotable External Tools Configurations gldb Reference fop gt E blenderjme Organize Favorites Wess_nine P EY hsqldb 1 4 Ehsqldb 16 b GBtmp switchedsrc b bin b build P doc b doc sre IF Prob 3 v 0 gt ei aoe e P amp sample 2 errors 0 warnings 0 others Y rc Description v g org b 9 Errors 2 items v g hsqldb meme Jaf Invoking Gradle GUI from Eclipse You can do this and close it after each use or to avoid startup lag minim
4. This property when set TRUE enables support for some elements of Oracle syntax The DUAL table is supported together with ROWNUM NEXTVAL and CURRVAL syntax and semantics The non standard types are translated to supported standard types BINARY DOUBLE and BINARY FLOAT are translated to DOUBLE LONG RAW and RAW are translated to VARBINARY with long or medium length limits LONG and VARCHARQ are translated to VARCHAR with long or medium length limits NUMBER is translated to DECIMAL Some extra type conversions and no arg functions are also allowed in this mode The property is FALSE by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sql syntax ora SET DATABASE SQL SYNTAX PGS set database sql syntax PGS set database sql syntax PGS statement SET DATABASE SQL SYNTAX PGS TRUE FALSE This property when set TRUE enables support for some elements of PosgtreSQL syntax The TEXT data type is translated to LONGVARCHAR while the SERIAL data types is translated to BIGINT together with GENERATED BY DEFAULT AS IDENTITY Single row SELECT statements SELECT expression list without the FROM clause are supported and treated as the SQL Standard equivalent VALUES lt expression list gt The functions NEXTVAL lt sequenc nam string CURRVAL lt sequenc name string and LASTVAL are supported in this compatibility mode
5. s sss 5 1 4 specifying a connection property to shutdown the database when the last connection is closed 7 1 5 specifying a connection property to disallow creating a new database sss 7 3 1 User defined Session Variables cst mm w pie data mak mp l bin it ke n EYE ve D Re m 31 3 2 User defined Temporary Session Tables 2 eorr e Son e iban a ee Easa n EE EON aana 31 3 3 Setting Transaction Characteristics a5 0cisaes stetas vap baiki an bibit snes CERE cass enon mw Re kal kak pal ae koka ki ERSE ped 37 3 4 Locking Tables srecetina ronnie kikit ki er jo ri fo pd a l EAE a pe pi lo kn 38 JI ROM dere kas m s ok kel iv al Sa e in e kn kl a l ek l ES LEO a VR Ne bik kt 38 3 6 Setting Session Characteristics Tm 39 3 7 Setting Session AULBODZatloD orosei ey bati sek tete ee do LETE E EREE vw pea so ka EEE aw Ran EE EESE PETECE epe KARA REE EENES 39 3 8 Setting Session TIMEZONE EE 40 4 1 inserting the next sequence value into a table row o oo sss HH ree 45 4 2 numbering returned rows of a SELECT in sequential order essem 45 4 3 using the last valu of a SEQUENCE i ouo coperte hare o teilte a bn oun de En cede save o EESE ET EEEn RUP pa oak dan 45 4 4 Column values which satisfy a 2 column UNIQUE constraint ssesesee teen eeeaeene een eegs 48 11 1 Using CACHED tables for the LOB schema see He Hem ehem herr 199 11 2 Of
6. sss e meme hen ent entren 259 Portability of Hsqldb imit SCHIpE lice teet tee eie ee SCIRE E SR De Ode Yea e Ex ee Ye ke eu e gece 260 Init SCript Setup Proced te etre rere emer els oie nee no end san E te k dikes none sy monite 260 Troubleshooting the Init Script cee cece e cence cece cece HH HH e mee emere ree 264 lacune m 265 15 Deployment GWAS 3 ree Root E E e desde snot teret E eon NI E den S ak er V FUCO MEE Y 266 Memory and Disk Use ie oos e vo eoe ot Pa ete aie Fer diee ves e suse reato va grade Dex pues sik euge se ke vite prosesis bwe 266 Table Memory Allocation 2 0 0 0 cece eli eee at eat HII emen e hen ent en hee eee eene 266 Result Set Memory Allocation 1iiieesie terrere eter ter eterno nane v ni sea e kepi kika seen bi 266 Temporary Memory Use During Operations sese HH re 267 Data Cache Memory ATlOCatlOT iere ror eterne e n ded e ve rong quer e bies s ore vg a Pa eode da Eee Was eo ed eu 267 Object Pool Memory Allocation esse HH I eI emnes hen t entree rennes 267 Lob Memory Usage n 268 Disk Space uio ete E iactu UU OR UR x tI e OS I aem te eU DP dam SA Pe Oke Ie 268 Managing Database Connections eeesseeseeeeee eene andose tenta ooh anon e sk an anie kone ae sud ne Eai 268 Tweaking the Mode of Operation sssesesee e mee HI hene hen hne hene herren 269 Application Development and Testing
7. sssssssessssssssssenee nemen ee he he ren rh eren eminere ree ne nnne 74 Name Information dwe pise coast excises TEUER 74 Data Type Information ente np detemine tr ness eoe ti getestet nE E a E ES E E E 75 Product Information 2e w eesti san ce ae a pin akte ko ve dad nan ce e De Ek m PERI W ka kk OR Re e RA 75 Operations InfOrMatlOM fe sw bone ou fes bosni bene po tense ri e e ea rice E a aiena E 75 SQL Standard VISWS eese edes cvv od eade eee suona vin exu xe vl quee sata edo volvo qe a ed eR Va 75 SENUOqMIIT ME 82 OVETVISW rr 82 The Implementation e ei ae e kwis an TEUER 82 Definition Of Tables err 82 Scope and RSASSIPNMEN seriearen eenen ON EEEE E EE E EESE EEEE 82 Null Values in Columns of Text Tables sssssssseseeeee eme ee emn emere nenne 83 iv HyperSGL HyperSQL User Guide OMS UTAM OU e konfere enko aie pen es costae von sot kaa den Sapoti pe ko bone ren ves soit adrese kak paO 83 Diseonnecting Text Lables iii zie dx noter Le ete Pire de ours ent e ter Eo Donee Ee aeaebyehedea tock 84 Text Pile USage 2x troie ro tise e rope eese Forbes e tn r s yen nanye aA bet voro sey edike SAN pte lpok Sans stus 85 Text File Global Properties ae ateste eee teo eie eres eek lesiv ae ce ete dive tte ke pep esp eo uiae ure ie 85 Transac HONS mn teye kit tett ka A a pa cores 86 up eucraSo IMP
8. schema definition CREATE SCHEMA schema name clause schema character set specification schema element schema name clause schema name gt AUTHORIZATION authorization identifier schema name AUTHORIZATION authorization identifier 51 HyperSGL Schemas and Database Objects If the name of the schema is specified simply as schema name then the AUTHORIZATION is the current user Otherwise the specified authorization identifier is used as the AUTHORIZATION for the schema If schema name is omitted then the name of the schema is the same as the specified authorization identifier schema element table definition view definition domain definition character set definition collation definition transliteration definition assertion definition trigger definition user defined type definition lt user defined cast definition lt user defined ordering definition transform definition schema routine sequence generator definition grant statement role definition An example of the command is given below Note that a single semicolon appears at the end there should be no semicolon between the statements CREATE SCHEMA ACCOUNTS AUTHORIZATION DBA CREATE TABLE AB A INTEGER CREATE TABLE CD C CHAR 10 CREATE VIEW VI AS SELECT GRANT SELECT ON AB TO PUBLIC GR
9. An optional property to override default text table settings The string literal has the same format as the string used for setting the data source of a text table but without the file name See the Text Tables chapter Only a user with the DBA role can execute this statement SQL Conformance Settings These statements modify the level of conformance to the SQL Standard in different areas The settings that specify SOL SYNTAX are for compatibility with other database engines and are FALSE by default For all the rest of the settings TRUE means better conformance to the Standard unless the Standard defines the behaviour as implementation dependent The default value of a few of these settings is FALSE due to widespread non conforming statements that are already in use in user applications or statements generated by object relational tools So long as it is practical it is best to set the non conforming defaults to TRUE in order to improve the quality of the database application SET DATABASE SQL SIZE set database sql size statement set database sql size statement SET DATABASE SQL SIZE TRUE FALSE Enable or disable enforcement of column sizes for CHAR and VARCHAR columns The default is TRUE meaning table definition must contain VARCHAR n instead of VARCHAR SQL Standard requires enforcement Only a user with the DBA role can execute this statement This is equivalent to the connection pr
10. TRIGGER EXECUTION ORDER trigger execution order 170 HyperSGL Triggers lt trigger execution order gt BEFORE lt other trigger name gt HyperSQL extends the SQL Standard to allow the order of execution of a trigger to be specified by using BEFORE lt other trigger name gt in the definition The newly defined trigger will be executed before the specified other trigger If this clause is not used the new trigger is executed after all the previously defined triggers of the same scope BEFORE AFTER EACH ROW EACH STATEMENT DROP TRIGGER drop trigger statement lt drop trigger statement gt DROP TRIGGER lt trigger name gt Destroy a trigger 171 HyperSQL Chapter 10 Built In Functions Fred Toussi The HSQL Development Group Revision 5049 Copyright 2010 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Overview HyperSQL supports a wide range of built in functions and allows user defined functions written in SQL and Java languages User defined functions are covered in the SQL Invoked Routines chapter If a built in function is not available you can write your own using procedural SQL or Java Built in agg
11. sss HH emere 269 Embedded Databases in Desktop Applications see 270 Embedded Databases in Server Applications sese 270 Mixed Mode Embedding a HyperSQL Server Listener eee 270 Using HyperSQL Without Logging Data Change see 270 Bulk Inserts Updates and Deletes sess mH mee mener een 271 viii HyperSQL HyperSQL User Guide Using NIO Ele ACCeSS iuo esee ee deett tatolete des ead epe erre sev dese tote tet e pea ses ei aa ene akte pakab esye 271 Server hcc Wc mE 271 Upgrading Databases 5 5 te des wes eerte to epike donn s ott Re ror eere sereni bos e E s T REE REE epike aaa ka ror edns 271 Upgrading From Older Versions essee HH seen sess rene rertree 272 Manual Changes to the script File ssssssssssesseeeee e e e mH mH em enne 273 Backward Compatibility Issues 0 cece cece cee em menmem m eem ent en ee n e nen nenne 273 HyperSQL Dependency Settings for Applications essem 275 What Version to Pull scsi etti ewe we sinye ki dee ed er tav erexit aetas dene depo ol qu os tae dex kou bat 275 Using the HyperSQL Snapshot Repository esses HH Hee 275 Kanpe m ciun ert 276 A Lists of Key wolds eya dine pont iode troi Ribes eee A dette teke bonis Se a mesi is teeter e S 279 List of SQL Standard Keywords l ll lllllleeeeeeeee tree tenn e tea ne teaassooanroooneooaosreone
12. lt null call clause gt RETURNS NULL ON NULL INPUT CALLED ON NULL INPUT SAVEPOINT LEVEL transaction impact The lt savepoint level indication gt is used only for procedures and refers to the visibility of existing savepoints within the body of the procedure If NEW SAVEPOINT LEVEL is specified savepoints that have been declared prior to calling the procedure become invisible within the body of the procedure HyperSQL s implementation accepts only NEW SAVEPOINT LEVEL which must be specified Bal savepoint level indication NEW SAVEPOINT LEVEL OLD SAVEPOINT LEVEL DYNAMIC RESULT SETS returned result sets characteristic The lt returned result sets characteristic is used with SQL PSM and SQL JRT procedures not with functions The maximum number of result sets that a procedure may return can be specified with the clause below 142 HyperSQL SQL Invoked Routines The default is zero If you want your procedure to return result sets you must specify the maximum number of result sets that your procedure may return Details are discussed in the next sections returned result sets characteristic gt DYNAMIC RESULT SETS maximum returned result sets gt SQL Language Routines PSM The PSM Persistent Stored Module specification extends the SQL language with structures and control statements such as conditional and loop statements
13. With the other forms of INSERT the optional insert column list specifies to which columns of the table the new values are assigned In one form the inserted values are from a query expression and all the rows that are returned by the query expression are inserted into the table If the query expression returns no rows nothing is inserted In the other form a comma separated list of values called lt contextually typed table value constructor is used to insert one or more rows into the table This list is contextually typed because the keywords NULL and DEFAULT can be used for the values that are assigned to each column of the table The keyword DEFAULT means the default value of the column and can be used only if the target column has a default value or is an IDENTITY or GENERATED column of the table The lt override clause gt must be used when a value is explicitly assigned to a column that has been defined as GENERATED ALWAYS AS IDENTITY The clause OVERRIDE SYSTEM VALUE means the provided values are used for the insert while OVERRIDING USER VALUE means the provided values are simply ignored and the values generated by the system are used instead An array can be inserted into a column of the array type by using literals by specifying a parameter in a prepared statement or an existing array returned by query expression The last example below inserts an array The rows that are inserted into the table are che
14. date literal time literal timestamp literal date literal DATE date string GI lt time literal gt TIME lt time string gt lt timestamp literal gt TIMESTAMP lt timestamp string gt lt date string gt lt quote gt lt unquoted date string gt lt quote gt lt time string gt lt quote gt lt unquoted time string gt lt quote gt lt timestamp string gt lt quote gt lt unquoted timestamp string gt lt quote gt lt time zone interval gt lt sign gt lt hours value gt lt colon gt lt minutes value gt lt date value gt lt years value gt lt minus sign gt lt months value gt lt minus sign gt lt days value gt lt time value gt lt hours value gt lt colon gt lt minutes value gt lt colon gt lt seconds value gt lt interval literal gt INTERVAL lt sign gt lt interval string gt lt interval qualifier gt lt interval string gt lt quote gt lt unquoted interval string gt lt quote gt unquoted date string date value lt unquoted time string time value gt time zone interval 102 HyperSGL Data Access and Change unquoted timestamp string unquoted date string space unquoted time string unquoted interval string sign year month literal day time literal year month literal years value
15. END QUEUE lt integer literal gt NOWAIT CALL lt HSQLDB trigger class FON transition table or variable list transition table or variable gt transition table or variable OLD ROW AS old transition variable name gt NEW ROW AS new transition variable name OLD TABLE AS old transition table name gt NEW TABLE AS new transition table name gt old transition table name transition table name new transition table name transition table name transition table name lt identifier gt old transition variable name gt lt correlation name gt lt new transition variable name gt lt correlation name gt Trigger definition is a relatively complex statement The combination of lt trigger action time gt and lt trigger event gt determines the type of the trigger Examples include BEFORE DELETE AFTER UPDATE INSTEAD OF INSERT If the optional OF lt trigger column list is specified for an UPDATE trigger then the trigger is activated only if one of the columns that is in the trigger column list is specified in the UPDATE statement that activates the trigger If a trigger is FOR EACH ROW which is the default option then the trigger is activated for each row of the table that is affected by the execution of an SQL statement Otherwise it is activated once only per statement execution In the first case there i
16. Example 15 1 Using CACHED tables for the LOB schema SET TABLE SYSTEM LOBS BLOCKS TYPE CACHED SET TABLE SYSTEM LOBS LOBS TYPE CACHED SET TABLE SYSTEM LOBS LOB IDS TYPE CACHED Disk Space With file database the engine uses the disk for storage of data and any change For safely the engine backs up the data internally during operation Spare space at least equal to the size of the data and script file is needed The lobs file is not backed up during operation as it is not necessary for safety Managing Database Connections In all running modes server or in process multiple connections to the database engine are supported in process standalone mode supports connections from the client in the same Java Virtual Machine while server modes support connections over the network from several different clients Connection pooling software can be used to connect to the database but it is not generally necessary Connection pools may be used for the following reasons To allow new queries to be performed while a time consuming query is being performed in the background In HyperSQL blocking depends on the transaction control model the isolation level and the current activity by other sessions Tolimitthe maximum number of simultaneous connections to the database for performance reasons With HSQLDB this can be useful if your application is designed in a way that opens and closes connections for each small task Also the
17. The rows that are updated are checked against all the constraints that have been declared on the table The whole UPDATE operation fails if any row violates any constraint set clause list set clause list lt set clause list gt lt set clause gt lt comma gt lt set clause gt lt set clause gt lt multiple column assignment gt lt set target gt lt equals operator gt lt update source gt lt multiple column assignment gt lt set target list gt lt equals operator gt lt assigned row 134 HyperSGL Data Access and Change set target list left paren set target comma set target right paren assigned row contextually typed row value expression set target column name update source lt value expression lt contextually typed value specification Specify a list of assignments This is used in UPDATE MERGE and SET statements to assign values to a scalar or row target Apart from setting a whole target to a value a SET statement can set individual elements of an array to new values The last example below shows this form of assignment to the array in the column named B In the examples given below UPDATE statements with single and multiple assignments are shown Note in the third example a SELECT statement is used to provide the update values for columns A and C while the update value for column B is given separate
18. When two binary values are compared if one is of BINARY type then zero padding is performed to extend the length of the shorter string to the longer one before comparison No padding is performed with other binary types If the bytes compare equal to the end of the shorter value then the longer string is considered larger than the shorter string If BINARY is used without specifying the length the length defaults to 1 For the BLOB type the length limit can be defined in units of kilobyte K 1024 megabyte M 1024 1024 or gigabyte G 1024 1024 1024 using the multiplier If BLOB is used without specifying the length the length defaults to 16M binary string type BINARY left paren length right paren BINARY VARYING VARBINARY left paren length right paren LONGVARBINARY left paren length right paren binary large object string type binary large object string type BINARY LARGE OBJECT BLOB left paren large object length right paren length unsigned integer gt BINARY 10 VARBINARY 2 BINARY VARYING 2 BLOB 1000 BLOB 30K BINARY LARGE OBJECT 1M LONGVARBINARY Bit String Types The BIT and BIT VARYING types are the supported bit string types These types were defined by SQL 1999 but were later removed from the Standard Bit types represent bit maps of given lengths Each bit is 0 or 1 The
19. comma value expression array value constructor by query ARRAY left paren query expression order by clause right paren In the examples below arrays are constructed from values column references or variables function calls or query expressions ARRA Ipod a S ARRAY HOT COLD ARRAY vari var2 CURRENT DATE ARRAY SELECT lastname FROM namestable ORDER BY id Inserting and updating a table with an ARRAY column can use array constructors not only for updated column values but also in equality search conditions INSERT INTO t VALUES 10 ARRAY 1 2 3 ARRAY HOT COLD UPDATE t SET names ARRAY LARGE SMALL WHERE id 12 UPDATE t SET names ARRAY LARGE SMALL WHERE id lt 12 AND scores ARRAY 3 4 When using a PreparedStatement with an ARRAY parameter an object of the type java sql Array must be used to set the parameter The org hsqlab jdbc JDBCArrayBasic class can be used for constructing a java sql Array object in the user s application Code fragment below String sql UPDATE t SET names WHERE id PreparedStatement ps connection prepareStatement sql Object data new Object one two default types defined in org hsqldb types Type can be used org hsqldb types Type type org hsqldb types Type SQL VARCHAR DEFAULT JDBCArrayBasic array new JDBCArrayBasic data type ps setArray 1 array ps setine
20. common Sequence generator options common sequence generator options common sequence generator option 68 HyperSGL Schemas and Database Objects common sequence generator option sequence generator start with option basic sequence generator option basic sequence generator option sequence generator increment by option sequence generator maxvalue option sequence generator minvalue option sequence generator cycle option sequence generator data type option AS data type sequence generator start with option START WITH sequence generator start value sequence generator start value signed numeric literal sequence generator increment by option INCREMENT BY sequence generator increment sequence generator increment signed numeric literal sequence generator maxvalue option MAXVALUE sequence generator max value NO MAXVALUE sequence generator max value signed numeric literal lt sequence generator minvalue option gt MINVALUE lt sequence generator min value gt NO MINVALUE lt sequence generator min value gt lt signed numeric literal gt lt sequence generator cycle option gt CYCLE NO CYCLE Define a named sequence generator A SEQUENCE object generates a sequence of integers according to the specified rules The simple
21. constraint definition The table is at first empty and cannot be written to An additional SET command specifies the file and the separator character that the Text table uses SET TABLE tablename SOURCE quoted filename and options DESC Scope and Reassignment A Text table without a file assigned to itis READ ONLY and EMPTY Reassigning a Text Table definition to a new file has implications in the following areas 1 The user is required to be an administrator 82 HyperSGL Text Tables 2 Existing transactions are committed at this point 3 Constraints including foreign keys referencing this table are kept intact It is the responsibility of the administrator to ensure their integrity The new source file is scanned and indexes are built when it is assigned to the table At this point any violation of NOT NULL UNIQUE or PRIMARY KEY constraints are caught and the assignment is aborted However foreign key constraints are not checked at the time of assignment or reassignment of the source file Null Values in Columns of Text Tables Empty fields are treated as NULL These are fields where there is nothing or just spaces between the separators Quoted empty strings are treated as empty strings Configuration The default field separator is a comma A different field separator can be specified within the SET TABLE SOURCE statement For example to change the field separator for
22. lt SQL routine body rights clause SQL SECURITY INVOKER SQL SECURITY DEFINER lt SQL routine body SOL procedure statement lt external body reference EXTERNAL NAME external routine name lt parameter style clause parameter style SQL GENERAL deterministic characteristic DETERMINISTIC NOT DETERMINISTIC SQL data access indication NO SQL CONTAINS SQL READS SQL DATA MODIFIES SQL DATA lt null call clause gt RETURNS NULL ON NULL INPUT CALLED ON NULL INPUT lt maximum returned result sets gt lt unsigned integer gt Define an SQL invoked routine A few of the options are not used by HyperSQL and have default behaviours See the SQL Invoked Routines chapter for more details of various options and examples ALTER routine 67 HyperSGL Schemas and Database Objects alter routine statement alter routine statement ALTER specific routine designator alter routine characteristics RESTRICT routine body alter routine characteristics alter routine characteristic alter routine characteristic language clause parameter style clause SQL data access indication null call clause returned result sets characteristic alter routine body SQL routine body Alter the characteristic and t
23. match predicate part 2 overlaps predicate part 2 distinct predicate part 2 result result expression NULL result expression value expression Specify a conditional value The result of a case expression is always a value All the values introduced with THEN must be of the same type Some simple examples of the CASE expression are given below The first two examples return Britain Germany or Other country depending on the value of dialcode The third example uses IN and smaller than predicates CASE dialcode WHEN 44 THEN Britain WHEN 49 THEN Germany ELSE Other country END CASE WHEN dialcode 44 THEN Britain WHEN dialcode 49 THEN Germany WHEN dialcode 0 THEN bad dial code ELSE Other country END CASE dialcode WHEN IN 44 49 30 THEN Europe WHEN IN 86 91 91 THEN Asia WHEN lt 0 THEN bad dial code ELSE Other continent END The case statement can be far more complex and involve several conditions CAST cast specification cast specification CAST left paren cast operand gt AS cast target right paren cast operand gt value expression implicitly typed value specification cast target domain name data type Specify a data conversion Data conversion takes place automatically among variants of a general type For example numeric values are freely converted from one type to another in expressions Explic
24. An example of the use of the WITH clause is given above under UNNEST The query expression in the WITH clause is evaluated once and its result table can be referenced in the body of the main query expression body using the specified query name The RECURSIVE keyword changes the way the elements of the with list are interpreted The query expression contained in the with list element must be the UNION or UNION ALL of two query expression body elements simple VALUES or SELECT statements The left element of the UNION is evaluated first and its result becomes the result of the with list element After this step the current result of the with list element is referenced in the right element a SELECT statement of the UNION the UNION is performed between the result and previous result of the with list element which is enlarged by this operation The UNION operation is performed again and again until the result of the with list element stops changing The result of the with list element is now complete and is later used in the execution of the query expression body When RECURSIVE is used the with column list must be defined HyperSQL limits recursion to 265 rounds If this is exceeded an error is raised A trivial example of a recursive query is given below Note the first column GEN For example if each row of the table represents a member of a family of dogs together with its parent the
25. In the example below the table contains a tree of rows each with a parent The routine returns an array containing the id list of all the direct and indirect children of the given parent The routine appends the array variable id_list with the id of each direct child and for each child appends the array with the id array of its children by calling the routine recursively The routine can be used in a SELECT statement as the example shows CREATE TABLE ptree pid INT id INT INSERT INTO ptree VALUES NULL 1 1 2 1 3 2 4 4 3 3 8 3 795 the function is created and always throws an exception when used CREATE FUNCTION child arr p pid INT RETURNS INT ARRAY SPECIFIC child arr one READS SOL DATA SIGNAL SQLSTATE 45000 the actual body of the function is defined replacing the statement that throws the exception ALTER SPECIFIC ROUTINE child arr one BEGIN ATOMIC DECLARE id list INT ARRAY DEFAULT ARRAY for loop FOR SELECT id FROM ptree WHERE pid p pid DO SET 1d list CARDINALITY el list 1 i0 SET ad list 1d lrst I cmila acrid END FOR for loop RETURN id list END 155 HyperSQL SQL Invoked Routines the function can now be used in SQL statements SELECT FROM TABLE child arr 2 In the next example a table with two columns is returned instead of an array In this example a local table variable is declared and filled with the children and the children s
26. Note that SqlTool can not shut down an embedded Derby database properly Since that requires an additional SQL connection just for that purpose However I ve never lost data by not shutting it down properly Other than not supporting this quirk of Derby SqliTool is miles ahead of ij We will be using the localhost sa sample urlid definition from the config file The JDBC URL for this urlid is jdbc hsqldb hsql localhost That is the URL for the default catalog of a HyperSQL Listener running on the default port of the local host You can read about URLs to connect to other catalogs with and without listeners in other chapters of this guide Run SqlTool java jar path to sqltool jar localhost sa If you get a prompt then all is well If security is of any concern to you at all then you should change the privileged password in the database Use the command SET PASSWORD command to change SA s password SET PASSWORD newpassword Set a strong password Note If like most UNIX System Administrators you often need to make up strong passwords I highly suggest the great little program pwgen https sourceforge net projects pwgen You can probably get it where you get your other OS packages The command pwgen 1 is usually all you need Note that with SQL conformant databases like HyperSQL 2 0 user names and passwords are case sensitive If you don t quote the name it will be int
27. Table 13 1 common server and webserver properties Value Default Description server database O file test the catalog type path and file name of the first database file to use server dbname 0 lowercase server alias for the first database file server database n NO DEFAULT the catalog type path and file name of the n th database file in use server dbname n NO DEFAULT lowercase server alias for the n th database file server silent no extensive messages displayed on console server trace JDBC trace messages displayed on console server address NO DEFAULT IP address of server server tls false Whether to encrypt network stream If this is set to true then in normal situations you will also need to set properties system javax net ssl keyStore and system javax net ssl keyStorePassword as documented elsewhere The value of server tls impacts the default value of server port server daemon false Whether the server is run as a daemon server remote_open false Allows opening a database path remotely when the first connection is made In HyperSQL version 2 0 each server can serve an unlimited number of databases simultaneously The server database O property defines the filename path whereas the server dbname 0 defines the lowercase alias used N 44 HyperSGL HyperSQL Network Listeners Servers by clients to connect to that database The digit 0 is incremented for the second database an
28. The property is FALSE by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sql syntax pgs SET DATABASE REFERENTIAL INTEGRITY set database referential integrity statement set database referential integrity statement SET DATABASE REFERENTIAL INTEGRITY TRUE FALSE This command enables or disables the enforcement of referential integrity constraints foreign key constraints check constraints apart from NOT NULL and execution of triggers By default all constraints are checked The only legitimate use of this statement is before importing large amounts of external data into tables that have existing FOREIGN KEY constraints After import the statement must be used again to enable constraint enforcement 220 HyperSGL System Management If you are not sure the data conforms to the constraints run queries to verify all rows conform to the FOREIGN KEY constraints and take appropriate actions for the rows that do not conform A query example to return the rows in a foreign key table that have no parent is given below Example 11 5 Finding foreign key rows with no parents after a bulk import SELECT FROM foreign key table LEFT OUTER JOIN primary key table ON foreign key table fk col primary key table pk col WHERE primary key table pk col IS NULL Only a user with the DBA role can execute this statement Ca
29. Two types of variables are allowed for mem and file database URLs If the database part of a file database begins with or the tilde character is replaced with the value of the system property user home resulting in the database being created or accessed in this directory or one of its subdirectories In the example below the database files for mydb are located in the user s home directory jdbc hsqldb file mydb shutdown true If the database URL contains a string in the form of propname then the sequence of characters is replaced with the system property with the given name For example you can use this in the URL of a database that is used in a web application and define the system property propname in the web application properties In the example below the string mydbpath is replaced with the value of the property mydbpath jabc hsqldb file mydbpath sql enforce types true Connection properties Each JDBC Connection to a database can specify connection properties The properties user and password are always required The following optional properties can also be used Connection properties are specified either by establishing the connection via the method call below or the property can be appended to the full Connection URL DriverManager getConnection String url Properties info Table 12 5 User and Password Name Default Description Standard property This
30. jdbc hsqldb file lt database path crypt key 604a6105889da65326bf35790a923932 crypt_type blowfish The third property name is crypt provider This is specified only when the provider is not the default provider HyperSQL works with any symmetric cipher that may be available from the JVM The files that are encrypted include the script data backup and log files The lobs file is not encrypted by default The property crypt_lobs true must be specified to encrypt the lobs file Speed Considerations General operations on an encrypted database are performed the same as with any database However some operations are significantly slower than with the equivalent cleartext database With MEMORY tables there is no difference 202 HyperSQL System Management to the speed of SELECT statements but data change statements are slower With CACHED tables the speed of all statements is slower Security Considerations Security considerations for encrypted databases have been discussed at length in HSQLDB discussion groups Development team members have commented that encryption is not a panacea for all security needs The following issues should be taken into account e Encrypted files are relatively safe in transport but because databases contain many repeated values and words especially known tokens such as CREATE INSERT etc breaking the encryption of a database may be simpler than an unknown file Only the files are enc
31. TIME and TIMESTAMP types can include WITH TIME ZONE or WITHOUT TIME ZONE the default qualifiers They can have fractional second parts For example TIME 6 has six fractional digits for the second field If fractional second precision is not specified it defaults to 0 for TIME and to 6 for TIMESTAMP datetime type DATE TIME left paren time precision right paren with or without time zone TIMESTAMP left paren timestamp precision right paren with or without time zone with or without time zone WITH TIME ZONE WITHOUT TIME ZONE time precision time fractional seconds precision timestamp precision time fractional seconds precision time fractional seconds precision unsigned integer DATE TIME 6 TIMESTAMP 2 WITH TIME ZONE Examples of the string literals used to represent date time values some with time zone some without are below DATE 20 08 08 22 TIMESTAMP 2008 08 08 20 08 08 TIMESTAMP 2008 08 08 20 08 08 8 00 Beijing TIME 20 08 08 034900 TIME 20 208 08 054900 8 00 US Pacific Time Zone 17 HyperSGL SQL Language DATE values do not take time zones For example United Nations designates 5 June as World Environment Day which was observed on DATE 2008 06 05 in different time zones TIME and TIMESTAMP values without time zone usuall
32. lt expression gt The two other methods require the user to specify which columns should be returned either by column indexes or by column names With these methods there is no restriction on which columns of the inserted values to be returned This is especially useful when some columns have a default clause which is a function or when there are BEFORE triggers on the table that may provide the inserted value for some of the columns Update Statement UPDATE update statement searched update statement searched gt UPDATE lt target table gt AS lt correlation name gt SET lt set clause list gt WHERE lt search condition gt Update rows of a table An UPDATE statement selects rows from the lt target table gt using an implicit SELECT statement formed in the following manner SELECT FROM target table AS correlation name WHERE search condition Then it applies the SET set clause list expression to each selected row If the implicit SELECT returns no rows no update takes place When used in JDBC the number of rows returned by the implicit SELECT is returned as the update count If there are FOREIGN KEY constraints on other tables that reference the subject table and the FOREIGN KEY constraints have referential actions then rows from those other tables that reference the updated rows are updated according to the specified referential actions
33. regular expression is defined according to Java language regular expression rules HyperSQL REGEXP SUBSTRING REGEXP SUBSTRING char value expr gt regular expression Returns the first region in the char value expr gt that matches the regular expression The regular expression gt is defined according to Java language regular expression rules HyperSQL REGEXP_SUBSTRING_ARRAY REGEXP_SUBSTRING_ARRAY lt char value expr gt lt regular expression gt Returns all the regions in the the lt char value expr gt that match the lt regular expression gt The regular expression is defined according to Java language regular expression rules Returns an array containing the matching regions HyperSQL REPEAT REPEAT char value expr gt count Returns a character string based on char value expr gt repeated lt count gt times JDBC REPLACE REPLACE lt char value expr 1 gt lt char value expr 2 gt lt char value expr 3 gt Returns a character string based on lt char value expr 1 gt where each occurrence of lt char value expr 2 has been replaced with a copy of char value expr 3 Ifthe function is called with just two arguments the lt char value expr 3 gt defaults to the empty string and calling the function simply removes the occurrences of lt char value expr 2 from the first string JDBC REVERSE REVERSE lt char
34. schema name characteristic SCHEMA value specification schema name Set the default schema name for unqualified names used in SQL statements that are prepared or executed directly in the current sessions The effect of this lasts for the lifetime of the session The SQL Standard form requires the schema name as a single quoted string HyperSQL also allows the use of the identifier for the schema The current schema can be accessed with the CURRENT SCHEMA function SET PATH set path statement ll a set path statement ET lt SQL path characteristic gt 40 HyperSGL Sessions and Transactions SOL path characteristic PATH value specification Set the SOL path used to determine the subject routine of routine invocations with unqualified routine names used in SQL statements that are prepared or executed directly in the current sessions The effect of this lasts for the lifetime of the session SET MAXROWS set max rows statement set max rows statement SET MAXROWS unsigned integer literal The normal operation of the session has no limit on the number of rows returned from a SELECT statement This command set the maximum number of rows of the result returned by executing queries This statement has a similar effect to the setMaxRows int max method of the JDBC Statement interface but it affects the results returned from the next statement execution only After the execution
35. At the time of invocation the Java method is called and the returned ResultSet is transformed 139 HyperSQL SQL Invoked Routines into an SQL table The column types of the declared TABLE must match those of the ResultSet otherwise an exception is raised at the time of invocation Ifa lt returns table type gt is defined for an SQL PSM function the following expression is used inside the function to return a table RETURN TABLE query expression In the example blow a table with two columns is returned RETURN TABLE SELECT a b FROM atable WHERE e 10 Functions that return a table are designed to be used in SELECT statements using the TABLE keyword to form a joined table When a JDBC CallableStatement is used to CALL the function the table returned from the function call is returned and can be accessed with the getResultSet method of the CallableStatement lt returns clause gt RETURNS lt returns type gt lt returns type gt lt returns data type gt lt returns table type gt lt returns table type gt TABLE lt table function column list gt lt table function column list gt left paren table function column list element comma table function column list element right paren table function column list element column name data type returns data type data type routine body routine body Rout
36. Each table has a name space for the names of its columns Because a schema object is always in a schema and a schema always in a catalog it is possible and sometimes necessary to qualify the name of the schema object that is being referenced in an SQL statement This is done by forming an identifier chain In some contexts only a simple identifier can be used and the identifier chain is prohibited While in some other contexts the use of identifier chain is optional An identifier chain is formed by qualifying each object with the name of the object that owns its name space Therefore a column name is prefixed with a table name a table name is prefixed with a schema name and a schema name is prefixed with a catalog name A fully qualified column name is in the form catalog name schema name table name gt lt column name likewise a fully qualified sequence name is in the form catalog name gt lt schema name gt lt sequence name gt HyperSQL extends the SQL standard to allow renaming all database objects The ALTER RENAME TO command has slightly different forms depending on the type of object If an object is referenced in a VIEW or ROUTINE definition it is not always possible to rename it Character Sets A CHARACTER SET is the whole or a subset of the UNICODE character set A character set name can only be a regular identifier gt There is a separate name space for character sets There are several
37. ONLY OPEN OR ORDER OUT OUTER OVER OVERLAPS OVERLAY PARAMETER PARTITION PERCENT RANK PERCENTILE CONT PERCENTILE DISC POSITION POSITION REGEX POWER PRECISION PREPARE PRIMARY PROCEDURE RANGE RANK READS REAL RECURSIVE REF REFERENCES REFERENCING REGR AVGX REGR AVGY REGR COUNT REGR INTERCEPT REGR R2 REGR SLOPE REGR SXX REGR SXY e REGR SYY RELEASE REPEAT RESIGNAL RESULT RETURN RETURNS REVOKE e RIGHT ROLLBACK ROLLUP ROW ROW NUMBER ROWS SAVEPOINT SCOPE SCROLL SEARCH SECOND SELECT SENSITIVE SESSION USER SET SIGNAL SIMILAR SMALLINT SOME SPECIFIC SPECIFICTYPE SQL SQLEXCEPTION SQLSTATE e SOLWARNING SQRT STACKED START STATIC STDDEV POP STDDEV SAMP SUBMULTISET e SUBSTRING SUBSTRING REGEX SUM e SYMMETRIC SYSTEM SYSTEM USER TABLE TABLESAMPLE THEN TIME TIMESTAMP TIMEZONE HOUR TIMEZONE MINUTE TO TRAILING TRANSLATE TRANSLATE REGEX TRANSLATION TREAT TRIGGER TRIM TRIM ARRAY TRUE TRUNCATE UESCAPE UNDO UNION UNIQUE UNKNOWN UNNEST UNTIL UPDATE UPPER USER USING VALUE VALUES VAR POP VAR SAMP VARBINARY VARCHAR VARYING WHEN WHENEVER WHERE WIDTH BUCKET WINDOW WITH WITHIN WITHOUT WHILE YEAR List of SQL Keywords Disallowed as HyperSQL Identifiers When the default SET DATABASE SQL NAMES FALSE mode is used only a subset of SOL Standard
38. These names can be used as column names but the names must be double quoted in SELECT and other statements 281 HyperSQL Appendix B Building HyperSQL Jars How to build customized or specialized jar files Fred Toussi The HSQL Development Group Revision 4909 2012 08 06 00 12 50 0100 Purpose From version 2 0 the supplied hsqldb jar file is built with Java 1 6 If you want to run with a 1 5 or older JVM or if you want to use an alternative jar hsqldb min jar etc you must build the desired jar with a Java SDK The Gradle task Ant target explainjars reports the versions of Java and Ant actually used Building with Gradle As noted above Java SDK 5 or later is required Unlike most software build systems you do not need to have the Gradle system installed on your computer to use it You don t need to understand the details to use it but this is the purpose of the gradlew wrapper scripts that you can see in HyperSQL s build directory If you want or need to learn more about Gradle you can start on the Gradle Documentation page http gradle org documentation on the Gradle web site http gradle org Gradle honors JAVA HOME Gradle can find the Java to use by finding out where java is available from but if environmental variable JAVA HOME is set that will override Therefore if you have multiple JREs or JDKs installed or don t know if multiple are installed you should set environmental variable JAVA
39. catalog consists of between 2 to 6 files all named the same but with different extensions located in the same directory For example the database named test consists of the following files test properties test script test log test data test backup test lobs The properties file contains a few settings about the database The script file contains the definition of tables and other database objects plus the data for non cached tables The log file contains recent changes to the database The data file contains the data for cached tables and the backup file is a compressed backup of the last known consistent state of the data file All these files are essential and should never be deleted For some catalogs the test data and test backup files will not be present In addition to those files a HyperSQL database may link to any formatted text files such as CSV lists anywhere on the disk While the test catalog is open a test log file is used to write the changes made to data This file is removed at a normal SHUTDOWN Otherwise with abnormal shutdown this file is used at the next startup to redo the changes Atest lck file is also used to record the fact that the database is open This is deleted at a normal SHUTDOWN Note When the engine closes the database at a shutdown it creates temporary files with the extension new which it then renames to those listed above These files should not be deleted by the user At
40. hsqldb nio_max_size nio buffer size limit The maximum size of data file in mega bytes that can use the nio access method When the file gets larger than this limit non nio access methods are used Values 64 128 256 512 1024 and larger multiples of 512 can be used The default is 256MB SET FILES NIO SIZE lt numeric value gt Table 12 54 Recovery Log Processing Name Description hsqldb full_log_replay recovery log processing The log file is processed during recovery after a forced shutdwon Out of memory conditions always abort the startup Any other exception stops the processing of the log file and by default continues the startup process If this property is true the startup process is stopped if any exception occurs Exceptions are usually caused by incomplete lines of SQL statements near the end of the log file which were not fully synced to disk when an abnormal shutdown occurred This property cannot be set with an SQL statement Table 12 55 Default Properties for TEXT Tables Description textdb default properties for new text tables Properties that override the database engine defaults for newly created text tables Settings in the text table SET tablename SOURCE source string command override both the engine defaults and the database properties defaults Individual textdb properties are listed in the Text Tables chapter Table 12 56
41. its users and its schema objects If file name gt is not specified the statements are returned in a ResultSet with each row containing an SQL statement No data statements are included in this form The optional file name is a single quoted string If file name is specified then the script is written to the named file In this case all the data in all tables of the database is included in the script as INSERT statements Only a user with the DBA role can execute this statement Database Settings These statements change the database settings SET DATABASE COLLATION set database collation statement set database collation statement SET DATABASE COLLATION collation name NO PAD PAD SPACE Each database can have its own default collation Sets the collation from the set of collations supported by HyperSQL Once this command has been issued the database can be opened in any JVM and will retain its collation All collations pad the shorter string with spaces when two strings are compared If NO PAD is specified comparison is performed without padding The default system collation is named SQL TEXT To use the default without padding use SET DATABASE COLLATION SQL TEXT NO PAD Only a user with the DBA role can execute this statement SET DATABASE DEFAULT RESULT MEMORY ROWS set database default result memory rows statement 211 HyperSGL System Management set database default result memory r
42. lt table subquery gt CREATE TABLE t a b c AS SELECT FROM atable WITH DATA column definition A column definition consists of a column name gt and in most cases a data type or domain name gt as minimum The other elements of column definition gt are optional Each column name gt in a table is unique column definition column name data type or domain name default clause identity column specification identity column sequence Specification generation clause column constraint definition collate clause data type or domain name data type domain name column constraint definition constraint name definition column constraint constraint characteristics column constraint NOT NULL unique specification references Specification check constraint definition A column constraint definition is a shortcut for a table constraint definition A constraint that is defined in this way is automatically turned into a table constraint A name is automatically generated for the constraint and assigned to it 53 HyperSGL Schemas and Database Objects Ifa collate clause is specified then a UNIQUE or PRIMARY KEY constraint or an INDEX on the column will use the specified collation Otherwise the default collation for the database is used generated columns The va
43. lt user defined aggregate function gt CREATE AGGREGATE FUNCTION lt schema qualified routine name gt SQL aggregate parameter declaration list returns clause routine characteristics routine body The parameter declaration list BNF is given below The type of the first parameter is used when the function is invoked as part of an SQL statement When multiple versions of a function are required each version will have the first parameter of a different type SQL aggregate declaration list left paren IN SQL parameter name lt parameter type comma IN SOL parameter name BOOLEAN comma INOUT SOL parameter name parameter type comma INOUT SQL parameter name lt parameter type right paren The return type is user defined This is the type of the resulting value when the function is called Usually an aggregate function is defined with CONTAINS SQL as it normally does not read the data in database tables but it is possible to define the function with READS SQL DATA and access the database tables When a SQL statement that uses the aggregate function is executed HyperSQL invokes the aggregate function with all the arguments set once per each row in order to compute the values Finally it invokes the function once more to return the final result In the computation phase the first argument is the value of the user argument as specified in the SQL s
44. raw paeezibe seksaass pr ode irte oe roe s k bit ea e be v odes uberis ves sold E PER AYE Gi saka san 204 Server Operation Monitoring e eme emen ent ent e mee nre nen nennen 204 Database eddy 204 xrwnsdadiboculi der UEM 204 Authentication Control 4 oris rore esos ah hl be repe ske Do pain pese renes evt koke ces Po kod ee Se pese pie 205 Compatibility with Other RDBMS ooo eee cence cece a eeea ceca cena cena eeae eem ee he mee hee nennen 205 PostgreSQL Compatibility secsnS aceguseccosepecsdvedsyasnnesussrmdegupescar E R EE EEEE vores sasa 206 MySQL Compatibility eocena lect cd sea y de kak kore e ei FE PSONN eke E SR opa s se e ke Te DIS 207 Firebird Compatibility sccssdicscuccav ERES 208 Apache Derby Compatibility eee ec cece cece cece ee e eme He HH Hm emm emen renes 208 Oracle Compatibility dod erto rostros ose vie ee teo ser or terti es ees dese E ee genus du ert upU E perve gebe pena 208 IDB2 Compatibility rc M 208 MS SQLServer and Sybase Compatibility essere 209 Kirmes 209 System Operations x e ocrestescedisor vesi kk donate en da ee pevded berger ofa ecd qu Pes es EE a acens 209 lboichzrcf np de mr 211 SQL Conformance Sei gs sessio eroe sin tol esee roses pe onebes vore sag sms dese un erdt de EEE E kode ve 214 Cache Persistence and Files Settings 2 0 0 ceeeceeeeceecneceeeneceeeeeeaeeeceeeeeaeceeaeeneeaeeeeaeen
45. register 0 doubleValue double b 1 double counter 0 return Double valueOf java lang Math pow a b if in null return null if in doubleValue 0 return null if register 0 null register 0 in counter 0 Integer valueOf 1 else register 0 Double valueOf register 0 doubleValue in doubleValue counter 0 Integer valueOf counter 0 intValue l return null In a select statement the function is used exactly like the built in aggregate functions SELECT geometric_mean age FROM FROM customer 164 HyperSGL Chapter 9 Triggers Fred Toussi The HSQL Development Group Revision 3042 Copyright 2010 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Overview Trigger functionality first appeared in SQL 1999 Triggers embody the live database concept where changes in SQL data can be monitored and acted upon This means each time a DELETE UPDATE or INSERT is performed additional actions are taken by the declared triggers SQL Standard triggers are imperative while the relational aspects of SQL are declarative Triggers allow performing an arbitrary transformation of data tha
46. right paren character length unsigned integer char length units large object length length multiplier large object length token character large object length large object length char length units large object length token digit multiplier multiplier K M G lt char length units gt CHARACTERS OCTETS CHAR 10 CHARACTER 10 VARCHAR 2 CHAR VARYING 2 CLOB 1000 CLOB 30K CHARACTER LARGE OBJECT 1M 14 HyperSGL SQL Language LONGVARCHAR Binary String Types The BINARY BINARY VARYING and BLOB types are the SQL Standard binary string types VARBINARY and BINARY LARGE OBJECT are synonyms for BINARY VARYING and BLOB types HyperSQL also supports LONGVARBINARY as a synonym for VARBINARY You can set LONGVARBINARY to map to BLOB with the sql longvar is lob connection property or the SET DATABASE SQL LONGVAR IS LOB TRUE statement Binary string types are used in a similar way to character string types There are several built in functions that are overloaded to support character binary and bit strings The BINARY type represents a fixed width string Each shorter string is padded with zeros to fill the fixed width Similar to the CHARACTER type the trailing zeros in the BINARY string are simply discarded in some operations For the same reason it is best to avoid this particular type and use VARBINARY instead
47. the OUT and INOUT arguments are passed as a single element array The static method can modify the OUT or INOUT argument by assigning a value to the sole element of the argument array procedure can return one or more result sets These are instantiated as JDBC ResultSet objects by the Java static and returned in array arguments of the method The signature of the Java method for a procedure that has N declared parameters and returns M result sets has the following pattern The N parameters corresponding to the signature of the declared SQL procedure are defined first followed by M parameters as ResultSet arrays When the SQL procedure is executed the Java method is called with single element array arguments passed for OUT and INOUT SQL parameters and single element arrays of ResultSet for the returned ResultSet objects The Java method may call the execute or executeQuery methods of JDBC Statement or PreparedStatement objects that are declared within the method and assign the ResultSet objects to the first element of each ResultSet argument For the returned ResultSet objects the Java method should not call the methods of java sql ResultSet before returning void methodName argl argN ResultSet ri ResultSet rM f the procedure contains SQL statements only statements for data access and manipulation are allowed The Java method should not perform commit or rollback The SQL statements should not change the
48. then the statement does not return an error if the drop statement is Issued on a non existent object SPECIFIC specific routine designator specific routine designator SPECIFIC routine type specific name routine type ROUTINE FUNCTION PROCEDURE This clause is used in statements that need to specify one of the multiple versions of an overloaded routine The specific name gt is the one specified in the routine definition statement 50 HyperSGL Schemas and Database Objects Renaming Objects RENAME rename statement HyperSQL rename statement ALTER object type name RENAME TO new name lt object type CATALOG SCHEMA DOMAIN TYPE TABLE CONSTRAINT INDEX ROUTINE SPECIFIC ROUTINE column renam Statement ALTER TABLE table name ALTER COLUMN name RENAME TO new name This statement is used to rename an existing object It is not part of the SQL Standard The specified name is the existing name which can be qualified with a schema name while the new name is the new name for the object Commenting Objects COMMENT comment statement HyperSQL comment statement COMMENT ON TABLE COLUMN ROUTINE name IS character string literal Adds a comment to the object metadata which can later be read from an INFORMATION SCHEMA view This command
49. urlid mem url jdbc hsqldb mem memdbid username SA password A personal local persistent database urlid personal url jdbc hsqldb file user home db personal shutdown true username SA password transiso TRANSACTION READ COMMITTED When connecting directly to a file database like this you should use the shutdown connection property like this to shut down the DB properly when you exit the JVM This is for a hsqldb Server running with default settings on your local computer and for which you have not changed the password for SA urlid localhost sa url jdbe hsqidb heql localhost username SA password Template for a urlid for an Oracle database You will need to put the oracle jdbc OracleDriver class into your classpath In the great majority of cases you want to use the file classesl2 zip which you can get from the directory SORACLE HOME jdbc lib of any Oracle installation compatible with your server Since you need to add to the classpath you can t invoke SqlTool with 256 HyperSGL HyperSQL on UNIX the jar swatch like java Jat sglbeol jar Put both the SqlTool jar and classes1l2 zip in your classpath and export andi run somethingi ike Yava org hsalabi ucr ogltToo lm nni umlutdec am diis url jdbc oracle thin Gaegir admc com 1522 TRAFFIC SID username blaine password secretpassword driver oracle jdbc OracleDriver Template for a TLS encrypte
50. 1og and script files The script file and the log file are read the next time the database is opened and the MEMORY tables are recreated with all their contents So unlike TEMPORARY tables MEMORY tables are persistent When the database is opened all the data for the memory tables is read and inserted This process may take a long time if the database is larger than tens of megabytes When the database is shutdown all the data is saved This can also take a long time CACHED tables are created with the CREATE CACHED TABLE command Only part of their data or indexes is held in memory allowing large tables that would otherwise take up to several hundred megabytes of memory Another advantage of cached tables is that the database engine takes less time to start up when a cached table is used for large amounts of data The disadvantage of cached tables is a reduction in speed Do not use cached tables if your data set is relatively small In an application with some small tables and some large ones it is better to use the default MEMORY mode for the small tables TEXT tables use a CSV Comma Separated Value or other delimited text file as the source of their data You can specify an existing CSV file such as a dump from another database or program as the source of a TEXT table Alternatively you can specify an empty file to be filled with data by the database engine TEXT tables are efficient in memory usage as they cache only part of the t
51. 23 up to 99 The year and month fields can hold zero unlike a TIMESTAMP value and the maximum value of a month field that is not the most significant field is 11 The standard function ABS lt interval value expression gt canbe used to convert a negative interval value to a positive one The literal representation of interval values consists of the type definition with a string representing the interval value inserted after the word INTERVAL Some examples of interval literal below TNTERVAT Vilas 28 12 19 3145 DAY S TO SECOND 8 INTERVAL 3503 12 19 345 HOUR TO SECOND S equal to the first value INTERVAL 19 345 SECOND 4 3 maximum number of digits for the second value is 4 and each value is expressed with three fraction digits INTERVAL 23 10 YEAR 2 TO MONTH Interval values of the types that are based on seconds can be cast into one another Similarly those that are based on months can be cast into one another It is not possible to cast or convert a value based on seconds to one based on months or vice versa When a cast is performed to a type with a smaller least significant field nothing is lost from the interval value Otherwise the values for the missing least significant fields are discarded Examples CAST INTERVAL 145 23 12 19 DAY TO SECOND AS INTERVAL DAY TO HOUR INTERVAL 145 23 DAY TO HOUR CAST INTERVAL 145 23 DAY TO HOUR AS INTERVAL DAY TO SECOND INTERVAL 14
52. 50 0100 This section explains how to encrypt the stream between JDBC network clients and HyperSQL Listeners If you are running an in process non Listener setup this chapter does not apply to you Requirements Hsqldb TLS Support Requirements Sun Java 2 x and up This is probably possible with IBM s Java but I don t think anybody has attempted to run HSQLDB with TLS under IBM s Java and I m sure that nobody in the HSQLDB Development Group has documented how to set up the environment e If Java 2 x or 3 x then you will need to install JSSE Your server and or client will start up much slower than that of Java 4 x users Client side users will not be able to use the https JDBC protocol because the https protocol handler is not implemented in 2 x 3 x Java JSSE if there is demand we could work around this A JKS keystore containing a private key in order to run a Listener If you are running the listener side then you ll need to run a HSQLDB Server or WebServer Listener instance It doesn t matter if the underlying database catalogs are new and it doesn t matter if you are making a new Listener configuration or encrypting an existing Listener configuration You can turn encryption on and off at will e You need a HSQLDB jar file that was built with JSSE present If you obtained your HSQLDB 1 7 2 or later distribution from us you are all set because we build with Java 1 4 or later which contains JSSE If you build your
53. A comma separated list of expressions enclosed in brackets with the optional keyword ROW In SQL a row containing a single element can often be used where a single value is expected 105 HyperSGL Data Access and Change set function specification set function specification set function specification aggregate function grouping operation grouping operation GROUPING left paren column reference comma column reference right paren Specify a value derived by the application of a function to an argument Early releases of HyperSQL 2 0 do not support grouping operation COALESCE coalesce expression coalesce expression COALESCE left paren value expression comma value expression right paren Replace null values with another value The coalesce expression has two or more instances of value expression If the first value expression evaluates to a non null value it is returned as the result of the coalesce expression If it is null the next value expression is evaluated and if it evaluates to a non non value it is returned and so on The type of the return value of a COALESCE expression is the aggregate type of the types of all the value expression instances Therefore any value returned is implicitly cast to this type HyperSQL also features built in functions with similar functionality NULLIF nullif expressio
54. AUTH FILE to the absolute path of HSQLDB OWNER s sq1tool rc file This file is read directly by root even if you run hsqldb as non root by setting HSOLDB OWNER in the config file If you copy the file make sure to use chmod to restrict permissions on the new copy The init script will abort with an appropriate exhortation if you have the permissions set incorrectly You need to set up a urlid stanza in your sq1tool rc file for network access i e JDBC URL with hsql hsqls http or https for each catalog in your server properties file For our example you need to define a 260 HyperSGL HyperSQL on UNIX 4 stanza for the file db0 db0 catalog You must supply for this catalog a hsql JDBC URL an administrative user name and the password Example 14 1 example sqltool rc stanza urlid locelhostdbl url gdbe hsqidb hsgqi5 localhost username SA password secret Look at the comment towards the top of the init script which lists recommended locations for the configuration file for various UNIX platforms Copy the sample config file sample hsqldb cfg to one of the listed locations your choice Edit the config file according to the instructions in it For our example you will set the value of URLIDS to localhostdbl since that is the urlid name that we used in the sq1tool rc file t SId hsqldb cfg 3583 2010 05 16 01 49 52Z unsaved gt Sample configuration file for HyperSQL Server Liste
55. BIT type represents a fixed width string Each shorter string is padded with zeros to fill the fixed with If BIT is used without specifying the length the length defaults to 1 The BIT VARYING type has a maximum width and shorter strings are not padded Before the introduction of the BOOLEAN type to the SQL Standard a single bit string of the type BIT 1 was commonly used For compatibility with other products that do not conform to or extend the SQL Standard HyperSQL allows values of BIT and BIT VARYING types with length 1 to be converted to and from the BOOLEAN type BOOLEAN TRUE is considered equal to B 1 BOOLEAN FALSE is considered equal to B O For the same reason numeric values can be assigned to columns and variables of the type BIT 1 For assignment the numeric value zero is converted to B O while all other values are converted to B 1 For comparison numeric values 1 is considered equal to B 1 and numeric value zero is considered equal to B O 15 HyperSGL SQL Language It is not allowed to perform other arithmetic or boolean operations involving BIT 1 and BIT VARYING 1 The kid of operations allowed on bit strings are analogous to those allowed on BINARY and CHARACTER strings Several built in functions support all three types of string bit string type BIT left paren length right paren BIT VARYING left paren length right paren BIT BIT TO BIT VARYING 2 Storage
56. Both SQL Function and SQL procedure bodies use the same syntax with minor exceptions The routine body is a SQL statement In its simplest form the body is a single SQL statement A simple example of a function is given below CREATE FUNCTION an_hour_before t TIMESTAMP RETURNS TIMESTAMP RETURN t HOUR An example of the use of the function in an SQL statement is given below SELECT an hour before event timestamp AS notification timestamp event name FROM events A simple example of a procedure is given below CREATE PROCEDURE new customer firstname VARCHAR 50 lastname VARCHAR 50 MODIFIES SQL DATA INSERT INTO CUSTOMERS VALUES DEFAULT firstname lastname CURRENT_TIMESTAMP The procedure inserts a row into an existing table with the definition given below CREATE TABLE customers id INTEGER GENERATED BY DEFAULT AS IDENTITY firstname VARCHAR 50 lastname VARCHAR 50 added TIMESTAMP An example of the use of the procedure is given below CALL new_customer JOHN SMITH The routine body is often a compound statement A compound statement can contain one or more SQL statements which can include control statements as well as nested compound statements Please note carefully the use of lt semicolon gt which is required at the end of some statements but not accepted at the end of others Advantages and Disadvantages SQL Language Routines PSM have certain advantage
57. DB2 style syntax This property when set true allows compatibility with some aspects of this dialect SET DATABASE SQL SYNTAX DB2 TRUE FALSE Table 12 25 MSSQL Style Syntax Name Default Description sql syntax mss support for MS SQL Server style syntax This property when set true switches the arguments of the CONVERT function and also allow compatibility with some other aspects of this dialect SET DATABASE SQL SYNTAX MSS TRUE FALSE Table 12 26 MySQL Style Syntax Name Default Description sql syntax mys support for MySQL style syntax This property when set true enables support for TEXT and AUTO INCREMENT types and also allow compatibility with some other aspects of this dialect SET DATABASE SQL SYNTAX MYS TRUE FALSE Table 12 27 Oracle Style Syntax Name Default Description sql syntax ora support for Oracle style syntax This property when set true enables support for non standard types It also enables DUAL ROWNUM NEXTVAL and CURRVAL syntax and and also allow compatibility with some other aspects of this dialect SET DATABASE SQL SYNTAX ORA TRUE FALSE Table 12 28 PostgreSQL Style Syntax Name Default Description sql syntax pgs support for PostgreSQL style syntax This property when set true enables support for TEXT and SERIAL types It also enables NEXTVAL CURRVAL and
58. For example TIME 12 00 00 is converted to TIME 12 00 00 8 00 when the session time zone displacement is 8 00 18 HyperSGL SQL Language Conversion between DATE and TIMESTAMP is performed by removing the TIME component of a TIMESTAMP value or by setting the hour minute and second fields to zero TIMESTAMP 2008 08 08 20 08 08 8 00 becomes DATE 2008 08 08 while DATE 2008 08 22 becomes TIMESTAMP 2008 08 22 00 00 00 Conversion between TIME and TIMESTAMP is performed by removing the DATE field values of a TIMESTAMP value or by appending the fields of the TIME value to the fields of the current session date value Assignment When a value is assigned to a datetime target e g a value is used to update a row of a table the type of the value must be the same as the target but the WITH TIME ZONE or WITHOUT TIME ZONE characteristics can be different If the types are not the same an explicit CAST must be used to convert the value into the target type Comparison When values WITH TIME ZONE are compared they are converted to UTC values before comparison If a value WITH TIME ZONE is compared to another WITHOUT TIME ZONE then the WITH TIME ZONE value is converted to AT LOCAL then converted to WITHOUT TIME ZONE before comparison It is not recommended to design applications that rely on comparisons and conversions between TIME values WITH TIME ZONE The conversions may involve normalisation of the time value resulting
59. GRANT EXECUTE ON ROUTINE aroutine TO approle REVOKE privilege revoke statement revoke privilege statement REVOKE GRANT OPTION FOR privileges FROM lt grantee gt comma grantee jJ GRANTED BY lt grantor gt RESTRICT CASCADE Revoke privileges from a user or role REVOKE role revoke role statement revoke role statement REVOKE ADMIN OPTION FOR role revoked comma role revoked FROM grantee comma grantee jJ GRANTED BY lt grantor gt RESTRICT CASCADE lt role revoked gt lt role name gt 93 HyperSGL Access Control Revoke a role from users or roles 94 HyperSQL Chapter 7 Data Access and Change Fred Toussi The HSQL Development Group Revision 5039 Copyright 2010 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Overview HyperSQL data access and data change statements are fully compatible with the latest SQL 2008 Standard There are a few extensions and some relaxation of rules but these do not affect statements that are written to the Standard syntax There is full support for classic SQL as
60. HOME to definitively eliminate all ambiguity o Rare Gotcha Depending on your operating system version and how you installed your JDK Gradle may not be able to find the JDK Gradle will inform you if this happens The easiest way to fix this problem is to set environmental variable JAVA_HOME to the root directory where your Java SDK is installed See previous note for justification So as not to get bogged down in the details here if you don t know how to set an environmental variable I ask you to utilize a search engine Invoking a Gradle Build Graphically Whether from an IDE a shortcut or launch icon to run a Gradle graphical build you just need to execute either the file gradle gui cmd on Windows or gradle gui all other platforms both of which reside in the build directory of your HyperSQL distribution I will explain how to invoke a graphical Gradle build from Windows Explorer and from Eclipse IDE Users of other operating systems should be able to infer how to use their own file manager in the same way as shown for Internet Explorer Users who want a desktop shortcut quick launch icon should first get Gradle working from a file manager like Windows Explorer then seek out instructions for making shortcuts etc for your operating system or desktop manager Try a web search Some IDEs like IntelliJ have direct support for Gradle The Spring Framework team is working on a sophisticated plugin for usi
61. J Date Database queries are data access statements The most commonly used data access statement is the SELECT statement but there are other statements that perform a similar role Data access statements access tables and return result tables The returned result tables are falsely called result sets as they are not necessarily sets of rows but multisets of rows Result tables are formed by performing the following operations on base tables and views These operations are loosely based on Relational Algebra JOIN operations SET and MULTISET operations SELECTION PROJECTION COMPUTING COLUMN NAMING GROUPING and AGGREGATION SELECTION AFTER GROUPING OR AGGREGATION SET and MULTISET COLLECTION OPERATIONS ORDERING SLICING Conceptually the operations are performed one by one in the above order if they apply to the given data access statement In the example below a simple select statement is made more complex by adding various operations CREATE TABLE atab le a INT D INT INI Q INT f NB INT in the next SELECT no join is performed and no further operation takes place SELECT FROM atable in the next SELECT selection is performed by the WHERE clause with no further action SELECT FROM atable WHERE a b c in the next SELECT projection is performed after the other operations SELECT d e f FROM atable WHERE a b c in the next SELECT computation is performed after projection
62. JAVA SPECIFIC NAME specific name The SPECIFIC lt specific name gt clause is optional but the engine will creates an automatic name if it is not present When there are several versions of the same routine the lt specific name gt is used in schema manipulation statements to drop or alter a specific version The lt specific name gt is a user defined name It applies to both functions and procedures In the examples below a specific name is specified for each function CREATE FUNCTION an_hour_before_or_now t TIMESTAMP RETURNS TIMESTAMP NO SOL LANGUAGE JAVA PARAMETER STYLE JAVA SPECIFIC an_hour_before_or_now_with_timestamp EXTERNAL NAME CLASSPATH org npo lib nowLessAnHour CREATE FUNCTION an_hour_before_max e_type INT RETURNS TIMESTAMP SPECIFIC an_hour_before_max_with_int RETURN SELECT MAX event_time FROM atable WHERE event type e type 1 HOUR DETERMINISTIC 141 HyperSQL SQL Invoked Routines deterministic characteristic The deterministic characteristic clause indicates that a routine is deterministic or not Deterministic means the routine does not reference random values external variables or time of invocation The default is NOT DETERMINISTIC It is essential to declare this characteristics correctly for an SQL JRT routine as the engine does not know the contents of the Java code which could include calls to methods returning random or time sensitive values lt
63. JDBC setting takes precedence Autocommit The autocommit property of a connection is a feature of JOBC and ODBC and is not part of the SQL Standard In autocommit mode all transactional statements are followed by an implicit commit In autocommit mode all ResultSet objects are read only and holdable JDBC Overview The JDBC settings ResultSet CONCUR READONLY and ResultSet CONCUR UPDATABLE are the available alternatives for read only or updatability The default is ResultSet CONCUR_READONLY The JDBC settings ResultSet TYPE FORWARD ONLY _ ResultSet TYPE SCROLL INSENSITIVE ResultSet TYPE SCROLL SENSITIVE are the available alternatives for both scrollability navigation and sensitivity HyperSQL does not support ResultSet TYPE_SCROLL_SENSITIVE The two other alternatives can be used for both updatable and read only result sets The JDBC settings ResultSet CLOSE_CURSORS_AT_COMMIT and ResultSet HOLD CURSORS OVER COMMIT are the alternatives for the lifetime of the result set The default is ResultSet CLOSE CURSORS AT COMMIT The other setting can only be used for read only result sets Examples of creating statements for updatable result sets are given below Connection c newConnection Statement st c setAutoCommit false st c createStatement ResultSet TYPE FORWARD ONLY ResultSet CONCUR_UPDATABLE Sit c createStatement ResultSet TYPE SCROLL INSENSITIVE ResultSet CONCUR UPDATABLE 97 Hy
64. JRT or SQL PSM routines Returning Data From Procedures The OUT or INOUT parameters of a PROCEDURE are used to assign simple values to dynamic parameters or to variables in the calling context According to the Standard an SQL PSM or SQL JRT procedure may also return result sets to the calling context These result sets are dynamic in the sense that a procedure may return a different number of result sets or none at all in different invocations The SQL Standard uses a mechanism called CURSORS for accessing and modifying rows of a result set one by one This mechanism is necessary when the database is accessed from an external application program The JDBC ResultSet interface allows this method of access from Java programs and is supported by HyperSQL HyperSQL support this method of returning single or multiple result sets from SQL PSM procedures only via the JDBC CallableStatement interface Cursors are declared and opened within the body of the procedure No further operation is performed on the cursors within the procedure When the execution of the procedure is complete the cursors become available as Java ResultSet objects via the CallableStatement instance that called the SQL PSM procedure The JDBC CallableStatement class is used with the SQL statement CALL lt routine name gt lt argument 1 to call procedures also to call functions After the call to execute the get XXX methods can be used to retrieve INOUT or OUT argum
65. MEMORY ROWS 41 SET TABLE CLUSTERED 58 SET TABLE read write property 58 SET TABLE SOURCE 58 SET TABLE SOURCE HEADER 59 SET TABLE SOURCE on off 60 SET TABLE TYPE 58 224 SET TIME ZONE 40 SET TRANSACTION 36 SHUTDOWN 209 SIGNAL STATEMENT 153 SIGN function 181 SIN function 181 SORT ARRAY function 190 sort specification list 131 SOUNDEX function 177 SPACE function 177 SPECIFIC 50 SPECIFIC NAME 141 SQL FEATURES 78 SQL IMPLEMENTATION INFO 78 SQL PACKAGES 78 SQL PARTS 78 SQL SIZING 78 SQL SIZING PROFILES 78 SQL DATA access characteristic 142 SQL parameter reference 104 SQL procedure statement 70 SQL routine body 140 SQRT function 181 START TRANSACTION 36 string value expression 109 SUBSTR function 177 SUBSTRING function 177 SYSDATE function 183 SYSTEM BESTROWIDENTIFIER 79 SYSTEM CACHEINFO 79 SYSTEM COLUMN SEQUENCE USAGE 80 SYSTEM COLUMNS 80 SYSTEM COMMENTS 80 SYSTEM CONNECTION PROPERTIES 80 SYSTEM CROSSREFERENCE 80 SYSTEM INDEXINFO 80 SYSTEM PRIMARYKEYS 80 SYSTEM PROCEDURECOLUMNS 80 SYSTEM PROCEDURES 80 SYSTEM PROPERTIES 80 SYSTEM SCHEMAS 80 SYSTEM SEQUENCES 80 SYSTEM SESSIONINFO 80 SYSTEM SESSIONS 80 SYSTEM TABLES 81 SYSTEM TABLETYPES 81 SYSTEM TEXTTABLES 81 SYSTEM TYPEINFO 81 SYSTEM UDTS 81 SYSTEM USER function 195 SYSTEM USERS 81 SYSTEM VERSIONCOLUMNS 81 SYSTIMESTAMP function 183 SYS USER 88
66. OF WEEK WEEK OF YEAR QUARTER DAY OF YEAR DAY OF MONTH TIMEZONE HOUR TIMEZONE MINUTE SECOND SECONDS SINCE MIDNIGHT DAY NAME MONTH NAM LH extract source datetime valu xpr gt interval value expr gt The EXTRACT function returns a field or element of the extract source The extract source gt isa datetime or interval expression The type of the return value is BIGINT for most ofthe extract field options The exceptions is SECOND where a DECIMAL value is returned which has the same precision as the datetime or interval expression The field values DAY NAME or MONTH NAME result in a character string When MONTH NAME is specified a string in the range January December is returned When DAY NAME is specified a string in the range Sunday Saturday is returned If the extract source gt isFROM datetime value expr gt different groups of extract source can be used depending on the data type of the expression The TIMEZONE HOUR TIMEZONE MINUTE options are valid only for TIME WITH TIMEZONE and TIMESTAMP WITH TIMEZONE data types The HOUR MINUTE SECOND SECONDS MIDNIGHT options are valid for TIME and TIMESTAMP types The rest of the fields are valid for DATE and TIMESTAMP types If the extract source isFROM interval value expr the extract field must be one of the fields of
67. SELECT d e f FROM atable WHERE a b c in the next two SELECT statements column naming is performed in different ways SELECT a e f AS calc f AS div FROM atable WHERE a b c SELECT deol ecol feol HROM atable acol beol ccol deol ecol Ecol WHERE acol beol ccol in the next SELECT both grouping and aggregation is performed SELECT d e SUM f FROM atable GROUP BY d e in the next SELECT selection is performed after grouping and aggregation is performed SELECT d e SUM f FROM atable GROUP BY d e HAVING SUM f gt 10 in the next SELECT a UNION is performed on two selects from the same table SELECT d e f FROM atable WHERE d 3 UNION SELECT a b c FROM atable WHERE a 30 in the next SELECT ordering is performed SELECT a e f AS calc f AS div FROM atable WHERE a b c ORDER BY calc DESC div NULLS LAST in the next SELECT slicing is performed after ordering SELECT FROM atable WHERE a b c ORDER BY a FETCH 5 ROWS ONLY 119 HyperSGL Data Access and Change The next sections discuss various types of tables and operations involved in data access statements Select Statement The SELECT statement itself does not cover all types of data access statements which may combine multiple SELECT statements The query specification is the most common data access statement and begins with the SELECT keyword SELECT STATEMENT select statemen
68. SET DATABASE SQL DOUBLE NAN FALSE The double values can be retrieved from a ResultSet in the required type so long as they can be represented For setting the values when PreparedStatement setDouble orsetFloat isused the value is treated as a DOUBLE automatically In short numeric type exact numeric type approximate numeric type lt exact numeric type NUMERIC left paren precision comma scale right paren DECIMAL DEC left paren precision comma scale right paren SMALLINT INTEGER INT BIGINT approximate numeric type FLOAT left paren precision right paren REAL DOUBLE PRECISION Xprecision unsigned integer scale unsigned integer Boolean Type The BOOLEAN type conforms to the SQL Standard and represents the values TRUE FALSE and UNKNOWN This type of column can be initialised with Java boolean values or with NULL for the UNKNOWN value The three value logic is sometimes misunderstood For example x IN 1 2 NULL does not return true if x is NULL In previous versions of HyperSQL BIT was simply an alias for BOOLEAN In version 2 0 BIT is a single bit bit map boolean type BOOLEAN The SQL Standard does not support type conversion to BOOLEAN apart from character strings that consists of boolean literals Because the BOOLEAN type is relative
69. SOURCE on off 60 SET TABLE TYPE 58 224 SET TIME ZONE 40 SET TRANSACTION 36 SHUTDOWN 209 SIGNAL STATEMENT 153 SIGN function 181 SIN function 181 SORT_ARRAY function 190 sort specification list 131 SOUNDEX function 177 SPACE function 177 SPECIFIC 50 SPECIFIC NAME 141 SQL_FEATURES 78 SQL_IMPLEMENTATION_INFO 78 SQL_PACKAGES 78 SQL_PARTS 78 SQL_SIZING 78 SQL_SIZING_PROFILES 78 SQL DATA access characteristic 142 SQL parameter reference 104 SQL procedure statement 70 SQL routine body 140 SQRT function 181 START TRANSACTION 36 string value expression 109 SUBSTR function 177 SUBSTRING function 177 SYSDATE function 183 SYSTEM_BESTROWIDENTIFIER 79 SYSTEM_CACHEINFO 79 SYSTEM_COLUMN_SEQUENCE_USAGE 80 SYSTEM_COLUMNS 80 SYSTEM_COMMENTS 80 SYSTEM_CONNECTION_PROPERTIES 80 SYSTEM_CROSSREFERENCE 80 SYSTEM_INDEXINFO 80 SYSTEM_PRIMARYKEYS 80 SYSTEM_PROCEDURECOLUMNS 80 SYSTEM_PROCEDURES 80 SYSTEM_PROPERTIES 80 SYSTEM_SCHEMAS 80 SYSTEM_SEQUENCES 80 SYSTEM_SESSIONINFO 80 SYSTEM_SESSIONS 80 SYSTEM_TABLES 81 SYSTEM_TABLETYPES 81 SYSTEM_TEXTTABLES 81 SYSTEM_TYPEINFO 81 SYSTEM_UDTS 81 SYSTEM_USER function 195 SYSTEM_USERS 81 SYSTEM_VERSIONCOLUMNS 81 SYSTIMESTAMP function 183 SYS USER 88 T TABLE 124 TABLE CONSTRAINTS 78 TABLE PRIVILEGES 78 TABLES 78 TAN function 181 TIMESTAMPADD function 186 TIMESTAMPDIFF function 186 TIMESTAMP function 188 Ti
70. SQL statement and is declared as FOR EACH STATEMENT A row level trigger is performed once for each row that is modified during the execution of an SQL statement and is declared as FOR EACH ROW Note that an SQL statement can INSERT UPDATE or DELETE zero or more rows If a statement does not apply to any row then the trigger is not executed If FOR EACH ROW or FOR EACH STATEMENT is not specified then the default is FOR EACH STATEMENT The granularity dictates whether the REFERENCING clause can specify OLD ROW NEW ROW or OLD TABLE NEW TABLE A trigger declared as FOR EACH STATEMENT can only be an AFTER trigger Trigger Action Time A trigger is executed BEFORE AFTER or INSTEAD OF the trigger event 166 HyperSGL Triggers INSTEAD OF triggers are allowed only when the trigger is declared on a VIEW With this type of trigger the event SQL statement itself is not executed only the trigger BEFORE or AFTER triggers are executed just before or just after the execution of the event For example just before a row is inserted into a table the BEFORE trigger is activated and just after the row is inserted the AFTER trigger is executed BEFORE triggers can modify the row that is being inserted or updated AFTER triggers cannot modify rows They are usually used to perform additional operations such as inserting rows into other tables A trigger declared as FOR EACH STATEMENT can only be an AFTER trigger References to Ro
71. Schemas and Database Objects routine characteristic language clause lt parameter style clause SPECIFIC specific name deterministic characteristic SQL data access indication lt null call clause returned result sets characteristic savepoint level indication OLD SAVEPOINT LEVEL savepoint level indication NEW SAVEPOINT LEVEL returned result sets characteristic DYNAMIC RESULT SETS maximum returned result sets a parameter style clause PARAMETER STYLE parameter style dispatch clause STATIC DISPATCH returns clause RETURNS returns type returns type returns data type result cast returns table type lt returns table type gt TABLE lt table function column list gt lt table function column list left paren table function column list element comma table function column list element right paren table function column list element column name data type result cast CAST FROM result cast from type result cast from type data type locator indication lt returns data type data type lt locator indication gt routine body lt SQL routine spec gt external body reference lt SQL routine spec gt rights clause
72. Specify a value computed from a collection of rows An aggregate function is used exclusively in a query specification gt and its use transforms a normal query into an aggregate query returning a single row instead of the multiple rows that the original query returns For example SELECT acolumn table expression isa query that returns the value of acolumn for all the rows the satisfy the given condition But SELECT MAX acolumn lt table expression gt returns only one row containing the largest value in that column The query SELECT COUNT lt table expression gt returns the count of rows while SELECT COUNT acolumn lt table expression gt returns the count of rows where acolumn IS NOT NULL If the lt table expression isa grouped table has a GROUP BY clause the aggregate function returns the result of the COUNT or lt computational operation gt for each group In this case the result has the same number of rows as the original grouped query For example SELECT SUM acolumn lt table expression gt when lt table expression gt hasaGROUP BY clause returns the sum of values for acolumn in each group The SUM operations can be performed on numeric and interval expressions only AVG and MEDIAN can be performed on numeric interval or datetime expressions AVG returns the average value while SUM returns the sum of all values If all values are NULL the operations return NULL MEDIAN returns the m
73. T TABLE 124 TABLE CONSTRAINTS 78 TABLE PRIVILEGES 78 TABLES 78 TAN function 181 TIMESTAMPADD function 186 TIMESTAMPDIFF function 186 TIMESTAMP function 188 Time Zone 17 TIMEZONE function 182 TO CHAR function 188 TO DATE function 189 TO NUMBER function 181 TO TIMESTAMP function 189 TODAY function 184 TRANSACTION CONTROL function 196 TRANSACTION ID function 196 TRANSACTION SIZE function 196 transaction characteristics 36 TRANSLATIONS 78 TRIGGER COLUMN USAGE 79 TRIGGER ROUTINE USAGE 79 300 HyperSQL SQL Index TRIGGER_SEQUENCE_USAGE 79 TRIGGER TABLE USAGE 79 TRIGGERED UPDATE COLUMNS 78 TRIGGERED SQL STATEMENT 170 TRIGGER EXECUTION ORDER 170 TRIGGERS 79 TRIM_ARRAY function 190 TRIM function 177 TRUNCATE function 181 TRUNCATE SCHEMA 132 TRUNCATE TABLE 132 TRUNC function datetime 188 TRUNC function numeric 181 U UCASE function 177 unicode escape elements 100 UNION JOIN 125 UNIQUE constraint 56 UNIQUE predicate 114 UNIX_TIMESTAMP function 185 UNNEST 123 UPDATE 134 UPPER function 178 USAGE_PRIVILEGES 79 USER_DEFINED_TYPES 79 USER function 194 UUID function 193 V value expression 108 value expression primary 104 value specification 105 VIEW COLUMN USAGE 79 VIEW ROUTINE USAGE 79 VIEW TABLE USAGE 79 VIEWS 79 W WEEK function 185 WHILE loop in routines 149 WIDTH_BUCKET function 182 Y YEAR function 185 301
74. The BNF definitions given here are sometimes simplified Literals Literals are used to express constant values The general type of a literal is known by its format The specific type is based on conventions 99 HyperSGL Data Access and Change unicode escape elements unicode escape elements Unicod scap specifier gt UESCAPE lt quote gt lt Unicode escape character gt lt quote gt lt Unicod scape value gt lt Unicode 4 digit escape value gt lt Unicode 6 digit escape value gt lt Unicode character escape value gt lt Unicode 4 digit escape value gt sye Unicode escape character gt lt hexit gt lt hexit gt lt hexit gt lt hexit gt Unicode 6 digit escape value Unicode escape character plus sign lt hexit gt lt hexit gt lt hexit gt lt hexit gt lt hexit gt lt hexit gt lt Unicode character escape value gt lt Unicode escape character gt lt Unicode escape character gt lt Unicode escape character gt a single character than a lt hexit gt a f A F 0 9 plus sign lt quote gt double quote gt or white space gt character literal character literal character string literal lt introducer gt lt character set specification gt quote character representation quote separator quote character representation quote J lt introducer gt lt underscore g
75. These statements perform a system level action SHUTDOWN shutdown statement shutdown statement SHUTDOWN IMMEDIATELY COMPACT SCRIPT Shutdown the database If the optional qualifier is not used a normal SHUTDOWN is performed A normal SHUTDOWN ensures all data is saved correctly and the database opens without delay on next use 209 HyperSGL System Management SHUTDOWN Normal shutdown saves all the database files then deletes the log file and the backup file in the default mode This does the same thing as CHECKPOINT but closes the database when it completes The database opens without delay on next used SHUTDOWN Saves the log file and closes the database files This is the quickest form of IMMEDIATELY shutdown This command should not be used as the routine method of closing the database because when the database is accessed next time it may take a long time to start SHUTDOWN COMPACT This is similar to normal SHUTDOWN but reduces the data file to its minimum size It can take much longer than normal SHUTDOWN This shouldn t be used as routine SHUTDOWN SCRIPT This is similar to SHUTDOWN COMPACT but it does not rewrite the data and text table files After SHUTDOWN SCRIPT only the script and properties files remain At the next startup these files are processed and the data file is created if there are cached tables This command in effect performs part of the job of SHUTDOWN COMP
76. This command does not change the properties or the name of the file that is the source of a text table When OFF is specified the command detaches the table from its source and closes the file for the source In this state it is not possible to read or write to the table This allows the user to replace the file with a different file or delete it When ON is specified the source file is read Only a user with the DBA role can execute this statement ALTER TABLE alter table statement alter table statement ALTER TABLE table name alter table action alter table action add column definition alter column definition drop column definition add table constraint definition drop table constraint definition Change the definition of a table Specific types of this statement are covered below ADD COLUMN add column definition add column definition ADD COLUMN column definition BEFORE other column name Add a column to an existing table The column definition is specified the same way as itis used in table definition HyperSQL allows the use of BEFORE other column name to specify at which position the new column is added to the table If the table contains rows the new column must have a default clause or use one of the forms of GENERATED The column values for each row is then filled with the result of the default clause or
77. a UUID hexadecimal string argument it returns the 16 byte binary value of the UUID With a 16 byte binary argument it returns the formatted UUID character representation HyperSQL System Functions CRYPT_KEY CRYPT_KEY lt value expr 1 gt lt value expr 2 gt 193 HyperSGL Built In Functions Returns a binary string representation of a cryptography key for the given cipher and cryptography provider The cipher specification is specified by value expr 1 and the provider by value expr 2 To use the default provider specify null for lt value expr 2 HypersQL DIAGNOSTICS DIAGNOSTICS ROW COUNT This is a convenience function for use instead of the GET DIAGNOSTICS statement The argument specifies the name of the diagnostics variable Currently the only supported variable is the ROW COUNT variable The function returns the row count returned by the last executed statement The return value is 0 after most statements Calling this function immediately after executing an INSERT UPDATE DELETE or MERGE statement returns the row count for the last statement as it is returned by the JDBC statement HyperSQL IDENTITY IDENTITY Returns the last IDENTITY value inserted into a row by the current session The statement CALL IDENTITY can be made after an INSERT statement that inserts a row into a table with an IDENTITY column The CALL IDENTITY statement returns the last IDENTITY value that was
78. according to strict rules of the database isolation model MVCC or LOCKS 200 HyperSGL System Management Durability means a committed transaction is protected in case of a system crash HyperSQL ensures durability according to the setting for WRITE DELAY MILLIS A zero delay setting results in an FileDescriptor sync call each time a transaction commits A timed delay means the FileDescriptor sync call is executed in the given intervals and only the last transactions committed in the interval may be lost The sync call is also made at all critical points including when a file is about to be closed Durability of files requires a reliable JVM and disk storage system that stores the data safely with a sync call In practice many systems are generally reliable in this respect Backing Up Database Catalogs The database engine saves the files containing all the data in a file catalog when a shutdown takes place It automatically recovers from an abnormal termination and preserves the data when the catalog is opened next time In an ideal operating environment where there is no OS crash disk failure bugs in code etc there would be no need regularly to backup a database This is meant to say the engine performs the routine shutdown procedure internally therefore backing up catalogs is an insurance policy against all sorts of misadventure that are not under the control of the database engine The data for each catalog consists of u
79. all quoted The ignore first option default false tells HSQLDB to ignore the first line in a file This option is used when the first line of the file contains column headings The all quoted option default false tells the program that it should use quotes around all character fields when writing to the source file The quoted option default true uses quotes only when necessary to distinguish a field that contains the separator character It can be set to false to prevent the use of quoting altogether and treat quote characters as normal characters These options may be specified within the SET TABLE SOURCE statement SET TABLE mytable SOURCE myfile ignore first true all quoted true When the default options all quoted false and quoted true are in force fields that are written to a line of the csv file will be quoted only if they contain the separator or the quote character The quote character is doubled when used inside a string When all quoted false and quoted false the quote character is not doubled With this option it is not possible to insert any string containing the separator into the table as it would become impossible to distinguish from a separator While reading an existing data source file the program treats each individual field separately It determines that a field is quoted only if the first character is the quote character It interprets the rest of the field on this basis The character encoding for
80. allows the use of vetted libraries In this case you vigorously maintain your configurations updating your dependencies and regression testing as soon as new versions of HyperSQL are vetted To get the best performance and reliability from HyperSQL you should urge the appropriate parties to vet new versions as soon as they are publicly released You need precisely reproducible builds If none of these situations apply to you then follow the suggestions in the appropriate sections below If you need to specify a specific version follow the instructions in the range versioning section but change the version range specifications to literal versions like 2 2 9 Using the HyperSQL Snapshot Repository Use the Latest amp Greatest with Snapshots The HyperSQL Snapshot repository resides at http hsqldb org repos Limitation of Classifiers Classifiers are incompatible with real repository snapshots Builders can only publish one jar variant per product and at this time our snapshot jars are always built debug enabled with Java 6 Where you insert the repository element depends on whether you want the definition to be personal shared or project specific so see the Maven documentation about that But you can paste this element verbatim Example 15 3 HyperSQL Snapshot Repository Definition repository releases lt enabled gt false lt enabled gt 275 HyperSGL Deployment Guide rel
81. and generation clause associated with the column definitions are copied or not If an option is not specified it defaults to EXCLUDING The generation clause refers to columns that are generated by an expression but not to identity columns All NOT NULL constraints are copied with the original columns other constraints are not The like clause can be used multiple times allowing the new table to have copies of the column definitions of one or more other tables CREATE TABLE t id INTEGER PRIMARY KEY LIKE atable INCLUDING DEFAULTS EXCLUDING IDENTITY like clause LIKE table name like options like options like option like option identity option column default option generation option identity option INCLUDING IDENTITY EXCLUDING IDENTITY column default option INCLUDING DEFAULTS EXCLUDING DEFAULTS lt generation option gt INCLUDING GENERATED EXCLUDING GENERATED as subquery clause lt as subquery clause gt lt left paren gt lt column name list gt lt right paren gt AS lt table subquery gt WITH NO DATA WITH DATA An as subquery clause used in table definition creates a table based on a table subquery gt This kind of table definition is similar to a view definition If WITH DATA is specified then the new table will contain the rows of data returned by the
82. and VIEW object including the INFORMATION SCHEMA views themselves TABLE CONSTRAINTS Information on all table level constraints including PRIMARY KEY UNIQUE FOREIGN KEY and CHECK constraints TABLE PRIVILEGES Information on privileges on TABLE and VIEW objects owned or given to the current user TRANSLATIONS TRIGGERED UPDATE COLUMNS 78 HyperSGL Schemas and Database Objects Information on columns that have been used in TRIGGER definitions in the ON UPDATE clause TRIGGERS Top level information on the TRIGGER definitions in the databases TRIGGER COLUMN USAGE Information on COLUMN objects that have been referenced in the body of TRIGGER definitions TRIGGER ROUTINE USAGE Information on FUNCTION and PROCEDURE objects that have been used in TRIGGER definitions TRIGGER SEQUENCE USAGE Information on SEQUENCE objects that been referenced in TRIGGER definitions TRIGGER TABLE USAGE Information on TABLE and VIEW objects that have been referenced in TRIGGER definitions USAGE PRIVILEGES Information on USAGE privileges granted to or owned by the current user USER DEFINED TYPES Top level information on TYPE objects in the database VIEWS Top Level information on VIEW objects in the database VIEW COLUMN USAGE Information on COLUMN objects referenced in the query expressions of the VIEW objects VIEW ROUTINE USAGE Information on FUNCTION and PROCEDURE objects that have been used in the query expressions of the VIEW objects V
83. and in their place the whole char value expr 2 is copied Equivalent to SQL Foundation OVERLAY char value exprl PLACING char value expr2 FROM offset FOR length JDBC HEXTORAW HEXTORAW char value expr gt Returns a BINARY string formed by translation of hexadecimal digits and letters in the char value expr Each character of the char value expr gt must be a digit or a letter in the AIBICIDIEIF set Each byte of the retired binary string is formed by translating two hex digits into one byte HyperSQL LCASE E LCASE lt char value expr gt Returns a character string that is the lower case version of the lt char value expr gt Equivalent to SQL Foundation LOWER char value expr gt JDBC LEFT LEFT lt char value expr gt lt count gt Returns a character string consisting of the first lt count gt characters of char value expr gt Equivalent to SQL Foundation SUBSTRING lt char value expr FROM 0 FOR count JDBC LENGTH LENGTH char value expr gt Returns as a BIGINT value the number of characters in lt char value expr gt Equivalent to SQL Foundation CHAR_LENGTH lt char value expr gt JDBC LOCATE LOCATE lt char value expr 1 gt lt char value expr 2 gt lt offset gt Returns as a BIGINT value the starting position of the first occurrence of char value expr 1 within char value expr 2 gt If lt offset
84. be disabled The operating system usually allocates a large amount of buffer memory for speed up file read operations Therefore when a lot of memory is available to the operating system all database operations perform faster Object Pool Memory Allocation HyperSQL uses a set of fast pools for immutable objects such as Integer Long and short String objects that are stored in the database In most circumstances this reduces the memory footprint still further as fewer copies of the most frequently used objects are kept in memory The object pools are shared among all databases in the JVM The size of each pool can be modified only by altering and recompiling the org hsqldb store ValuePool class 267 HyperSQL Deployment Guide Lob Memory Usage Access to lobs is always performed in chunks so it is perfectly possible to store and access a CLOB or BLOB that is larger than the JVM memory allocation The actual total size of lobs is almost unlimited We have tested with over 100 GB of lobs without any loss of performance By default HyperSQL 2 0 uses memory based tables for the lob schema not the actual lob data Therefore it is practical to store about 100 000 individual lobs in the database with the default JVM memory allocation More lobs can be stored with larger JVM memory allocations In order to store more than a few hundreds of thousands of lobs you can change the lob schema storage to CACHED tables with the following statements
85. been committed are not updated in the source file Therefore the source file always contains committed rows However text tables are not as resilient to machine crashes as other types of tables If the crash happens while the text source is being written to the text source may contain only some of the changes made during a committed transaction With other types of tables additional mechanisms ensure the integrity of the data and this situation will not arise 86 HyperSQL Chapter 6 Access Control Fred Toussi The HSQL Development Group Revision 3096 Copyright 2010 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Overview This chapter is about access control to database objects such as tables inside the database engine Other issues related to security include user authentication password complexity and secure connections are covered in the System Management chapter and the HyperSQL Network Listeners Servers chapter Apart from schemas and their object each HyperSQL catalog has USER and ROLE objects These objects are collectively called authorizations Each AUTHORIZATION has some access rights on some of the schemas or the objects they contain The persistent
86. can also be modified using an SQL statement You can use the statement to change only the isolation mode only the read only mode or both at the same time This command can be issued only after a commit or rollback SET TRANSACTION lt transaction characteristic gt comma transaction characteristic Details of the statement is described later in this chapter Session Attributes and Variables Each session has several system attributes A session can also have user defined session variables 30 HyperSGL Sessions and Transactions Session Attributes The system attributes reflect the current mode of operation for the session These attributes can be accessed with function calls and can be referenced in queries For example they can be returned using the VALUES attribute function statement The named attributes such as CURRENT USER CURRENT SCHEMA etc are SQL Standard functions Other attributes of the session such as auto commit or read only modes can be read using other built in functions All these functions are listed in the Built In Functions chapter Session Variables Session variables are user defined variables created the same way as the variables for stored procedures and functions Currently these variables cannot be used in general SQL statements They can be assigned to IN INOUT and OUT parameters of stored procedures This allows calling stored procedures which have INOUT or OUT arguments an
87. can be in join or WHERE clauses including all types of joins In addition HyperSQL will use an index if one exists for IN conditions whether constants variable or subqueries are used on the right hand side of the IN predicate Multicolumn IN conditions can also use an index HyperSQL can always use indexes when several conditions are combined with the AND operator choosing a conditions which can use an index This now extended to all equality conditions on multiple columns that are part of an index HyperSQL will also use indexes when several conditions are combined with the OR operator and each condition can use an index each condition may use a different index For example if a huge table has two separate columns for first name and last name and both columns are indexed a query such as the following example will use the indexes and complete in a short time TC is a very large table 27 HyperSGL SQL Language SELECT FROM TC WHERE TC FIRSTNAME John OR TC LASTNAME Smith OR TC LASTNAME Williams Each subquery is considered a separate SELECT statement and uses indexes when they are available In each SELECT statement at least one index per table can be used if there is a query conditions that can use the index When conditions on a table are combined with the OR operator and each condition can use an index multiple indexes per table are used Indexes and Operations HyperSQL optimis
88. can be opened as readonly To make the database readonly the property value pair readonly true can be added to the properties file of the database It is also possible to open a normal database as readonly For this the property can be included in the URL of the first connection to the database There is another option which allows MEMORY tables to be writeable but without persisting the changes at SHUTDOWN This option is activated with the property value pair fi les readonly true which can be added to the properties file of the database or included in the URL of the first connection to the database This option is useful for running application tests which operate on a predefined dataset ACID Persistence and Reliability HyperSQL 2 0 uses the same persistence mechanism as version 1 8 but with important enhancements The code has proven reliable as the last critical issue was fixed 2 years before the release of version 2 0 There are further enhancements in version 2 2 More extensive locking mechanism has been added to code to support multithreaded access ncremental backup an internal mechanism for crash protection allows fast checkpoint and shutdown All files are synced at checkpoints and also just before closing The data file is enlarged in block increments The NIO file access implementation has been improved Persistence relies on the JVM the operating system and the computer hardware A database system li
89. children CREATE FUNCTION child table p pid INT RETURNS TABLE r pid INT r id INT SPECIFIC child table one READS SQL DATA SIGNAL SQLSTATE 45000 ALTER SPECIFIC ROUTINE child table one BEGIN ATOMIC DECLARE TABLE child tree pid INT id INT for loop FOR SELECT pid id FROM ptree WHERE pid p pid DO INSERT INTO child tree VALUES pid id INSERT INTO child tree SELECT r pid r id FROM TABLE child table id END FOR for loop RETURN TABLE SELECT FROM child tree END SELECT FROM TABLE child table 1 Infinite recursion is not possible as the routine is terminated when a given depth is reached Java Language Routines SQL JRT The general features of SQL Invoked Routines are shared between PSM and JRT routines These features are covered in the previous section This section deals with specific aspects of JRT routines The body of a Java language routine is a static method of a Java class specified with a fully qualified method name in the routine definition A simple CREATE FUNCTION example is given below which defines the function to call the java lang Math sinh double d Java method The function can be called in SQL statements just like any built in function CREATE FUNCTION sinh v DOUBLE RETURNS DOUBLE LANGUAGE JAVA DETERMINISTIC NO SQL EXTERNAL NAME CLASSPATH java lang Math sinh SELECT sinh doublecolumn FROM mytable In the example below the static method named toZeroPaddedSt r
90. circumstances and disallowed in some others Schema objects can be destroyed with the DROP statement If dependent schema objects exist a DROP statement will succeed only if it has a CASCADE clause In this case dependent objects are also destroyed in most cases In 42 HyperSGL Schemas and Database Objects some cases such as dropping DOMAIN objects the dependent objects are not destroyed but modified to remove the dependency A new HyperSQL catalog contains an empty schema called PUBLIC By default this schema is the initial schema when a new session is started New schemas and schema objects can be defined and used in the PUBLIC schema as well as any new schema that is created by the user You can rename the PUBLIC schema HyperSQL allows all schemas to be dropped except the schema that is the default initial schema for new sessions by default the PUBLIC schema For this schema a DROP SCHEMA CASCADE statement will succeed but will result in an empty schema rather than no schema The statements for setting the initial schema for users are described in the Statements for Authorization and Access Control chapter Names and References The name of a schema object is an identifier The name belongs to the name space for the particular kind of schema object The name is unique within its name space For example each schema has a separate name space for TRIGGER objects In addition to the name spaces in the schema
91. clause is always included But the CREATE TABLE statements in your application program may assume an automatic primary key is created The old shortcut IDENTITY is retained with the same meaning So CREATE TABLE T ID IDENTITY DAT VARCHAR 20 is translated into CREATE TABLE T ID INTEGER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY DAT VARCHAR 20 This last form is the correct way of defining both autoincrement and primary key in versions 1 8 and 2 0 CREATE ALIAS is now obsolete Use the new function definition syntax The org hsqldb Library class no longer exists You should use the SQL form of the old library functions For example use LOG x rather than the direct form org hsqldb Library log x The names of some commands for changing database and session properties have changed See the list of statements in this chapter Computed columns in SELECT statements which did not have an alias These columns had no ResultMetaData label in version 1 8 but in version 2 0 the engine generates labels such as C1 C2 274 HyperSQL Deployment Guide e The issue with the JDBC ResultSetMetaData methods getColumnName int column and getColumnLabel int column has been clarified by the JDBC 4 specification get ColumName returns the underlying column name while getColumnLabel returns any specified or generated alias HyperSQL 1 8 and 2
92. connected with must have the role DBA or your account must have authorization for the target schema see the CREATE SCHEMA command about this last When you first create a HyperSQL catalog it has only one database user SA a DBA account with an empty string password You should set a password as described above You can create as many additional users as you wish To make a user a DBA you can use the ADMIN option to the CREATE USER command command or GRANT the DBA Role to the account after creating it Once an object is created the object creator and users with the DBA role will have all privileges to work with that object Other users will have only the rights which the pseudo user PUBLIC has To give specific users more permissions even rights to read objects you can GRANT permissions for specific objects grant Roles which encompass a set of permissions or grant the DBA Role itself Since only people with a database account may do anything at all with the database it is often useful to permit other database users to view the data in your tables To optimize performance reduce contention and minimize administration it is often best to grant SELECT to PUBLIC on table like objects that need to be accessed by multiple database users with the significant exception of any data which you want to keep secret Similarly with EXECUTE priv for routines and USAGE priv for other object types Note that this is not at all equiv
93. customer IN firstname VARCHAR 50 IN lastname VARCHAR 50 IN address VARCHAR 100 MODIFIES SOL DATA BEGIN ATOMIC DECLARE temp id INTEGER INSERT INTO CUSTOMERS VALUES DEFAULT firstname lastname CURRENT TIMESTAMP SET temp id IDENTITY INSERT INTO ADDRESSES VALUES DEFAULT temp id address END The BNF for variable declaration is given below DECLARE variable SQL variable declaration lt SQL variable declaration gt DECLARE lt variable name list gt lt data type gt DEFAULT lt default value gt lt variable name list gt lt variable name gt lt comma gt lt variable name gt Examples of variable declaration are given below Note that ina DECLARE statement with multiple comma separated variable names the type and the default value applies to all the variables in the list BEGIN ATOMIC DECLARE temp_zero DATE DECLARE temp_one temp_two INTEGER DEFAULT 2 DECLARE temp_three VARCHAR 20 DEFAULT no name more statements SET temp zero DATE 2010 03 18 SET temp two 5 jess SCACCMENES occ END Cursors A declare cursor gt statement is used to declare a SELECT statement The current usage of this statement in early versions of HyperSQL 2 0 is exclusively to return a result set from a procedure The result set is returned to the JDBC CallableStatement object that calls the procedure The getResultSet method of CallableStatement is then used to retrie
94. data in the database is called separately using the CALL statement can have parameters can be polymorphic Definition of routine signature and characteristics name resolution and invocation are all implemented uniformly for routines written in SQL or Java 138 HyperSQL SQL Invoked Routines Routine Definition SQL Invoked Routines whether PSM or JRT are defined using a SQL statement with the same syntax The part that is different is the lt routine body gt which consists of SQL statements in PSM routines or a reference to a Java method in JRT routines Details of Routine definition are discussed in this section You may start by reading the next two sections which provide several examples before reading this section for the details Routine definition has several mandatory or optional clauses The complete BNF supported by HyperSQL and the remaining clauses are documented in this section CREATE FUNCTION CREATE PROCEDURE routine definition Routine definition is similar for procedures and functions A function definition has the mandatory lt returns clause gt which is discussed later The description given so far covers the essential elements of the specification with the BNF given below schema procedure CREATE PROCEDURE schema qualified routine name SQL parameter declaration list routine characteristics routine body schema function CREATE FUNCTION schema q
95. definition without the options defines a sequence of numbers in INTEGER type starting at 1 and incrementing by 1 By default the CYCLE property is set and the minimum and maximum limits are the minimum and maximum limits of the type of returned values There are self explanatory options for changing various properties of the sequence The MAXVALUE and MINVALUE specify the upper and lower limits If CYCLE is specified after the sequence returns the highest or lowest value in range the next value will respectively be the lowest or highest value in range If NO CYCLE is specified the use of the sequence generator results in an error once the limit has been reached The integer types SMALLINT INTEGER BIGINT DECIMAL and NUMERIC can be used as the type of the sequence DECIMAL and NUMERIC types must have a scale of 0 and a precision not exceeding 18 ALTER SEQUENCE alter sequence generator statement lt alter sequenc generator statement gt ALTER SEQUENCE lt sequenc generator name gt lt alter sequence generator options gt lt alter sequence generator options gt lt alter sequence generator option gt lt alter sequence generator option gt lt alter sequence generator restart option gt lt basic sequence generator option gt lt alter sequence generator restart option gt RESTART WITH lt sequence generator restart value gt lt sequence generator rest
96. dest de an TES 48 TTIE SETS sssistecsicsacyonseseaesfalngavuedenisswrgacssnwareusative epe oil Se plas pen ve kt dalngevuedundesotedeessvormoasens 48 ROULNES reziste EE 49 Indexes lenn ear a yan ta os pe EESE ke Ane e dace kaa sa a ese ces E 49 Statements for Schema Definition and Manipulation sseeeeee meer 49 Common Elements and Statements sess me me mene sen nennen rennen ree rennes 49 Renaming ODJECtS dU 51 Commenting ODjectS 5 cocsvissadeciadanar GG 51 Schema Creation P 51 MADE CFEAN ON toye fi ak e mt ke ey vip ane fr irin ak nn t ko ke e ye pete ke ea e ka ie end en r l ed ia A 22 Table Manipulation serso sett etie tes bx ire icis key kek tein EUH te apes de uet de ak tas 58 View Creation and Manipulation sese eme emm mee men mene eee rennen 62 Domain Creation and Manipulation sssssessessee eem e mH mH mee en mener rene 63 ggg HR 64 Routine Creation CE 66 Nuper M 68 SOL Procedure Statement 1 ccce erit nr IE ERE E YO AR Fa Sed Eee EYE Nd Me QUU RA C dela 70 Other Schema Object Crean iore reete rette ies csnessv penis e be ebbe vo UR E pee siu ase ed SEP hi pon 70 The Information Schema 44 teeth te bean SA vi ee e kaa e E e Poe Red re pk dde 73 Predefined Character Sets Collations and Domains eee meme 74 Views in INFORMATION SCHEMA esee IH Hee Ie hee ree reeeree 74 Visibility of Information
97. die after all HSQLDB instances stopped Defaults to 60 Set high because the script will always continue as soon as the process has stopped The importance of this setting is how long until f a non stopping JVM problem will be detected MAX TERMINATE SECS O NEW AND IMPORTANT As noted at the top of this file this setting replaces the old property settings server urlid X Simply list the URLIDs for all DB instances which your Server starts Usually these will exactly mirror the server database X settings in your server properties or webserver properties file Each urlid listed here must be defined to a NETWORK url with Admin privileges in the AUTH_FILE specified below Network type because we use this for inter process communication Separate multiple values with white space NO OTHER SPECIAL CHARACTERS Make sure to quote the entire value if it contains white space separator s URLIDS localhostdbl aE Se SE NE db db dE db GE de de These are urlids IN ADDITION TO URLIDS for instances which the init script should stop but not start Most users will not need this setting If you need it you ll know it Defaults to none i e only URLIDS will be stopped SHUTDOWN URLIDS ondemand SglTool authentication file used only for shutdown The default value will be sqltool rc in root s home directory since it is root who runs the init script See the SqlTool chapter of the HyperSQL Utilitie
98. elements of an SQL environment are database objects Authorizations names are stored in the database in the case normal form When connecting to a database via JDBC the user name and password must match the case of this case normal form When a user is created with the CREATE USER statement if the user name is enclosed in double quotes the exact name is used as the case normal form But if it is not enclosed in double quotes the name is converted to uppercase and this uppercase version is stored in the database as the case normal form Authorizations and Access Control In general ROLE and USER objects simply control access to schema objects This is the scope of the SQL Standard However there are special roles that allow the creation of USER and ROLE objects and also allow some special operations on the database as a whole These roles are not defined by the Standard which has left it to implementers to define such roles as they are needed for the particular SQL implementation A ROLE has a name a collection of zero or more other roles plus some privileges access rights A USER has a name and a password It similarly has a collection of zero or more roles plus some privileges USER objects existed in the SQL 92 but ROLE objects were introduced in SQL 1999 Originally it was intended that USER objects would normally be the same as the operating system USER objects and their authentication would be handled outside the SQL environment The
99. existing values can be cast into the new type without string truncation or loss of significant digits 61 HyperSGL Schemas and Database Objects alter column add identity generator alter column add identity generator add column identity generator identity column specification Adds an identity specification to the column The type of the column must be an integral type and the existing values must not include nulls This option is specific to HyperSQL ALTER TABLE mytable ALTER COLUMN id GENERATED ALWAYS AS IDENTITY START WITH 20000 alter column identity generator alter identity column specification alter identity column specification alter identity column option alter identity column option alter sequence generator restart option SET basic sequence generator option Change the properties of an identity column This command is similar to the commands used for changing the properties of named SEQUENCE objects discussed earlier and can use the same options ALTER TABLE mytable ALTER COLUMN id RESTART WITH 1000 ALTER TABLE mytable ALTER COLUMN id SET INCREMENT BY 5 DROP GENERATED drop column identity generator drop column identity specification DROP GENERATED Removes the identity generator from a column After executing this statement the column values are no longer generated automatically This option is specific to HyperS
100. expressed as A JOIN B ON search condition Equijoin is a condition join in which the search condition is an equality condition between on or more pairs of columns from the two table Equijoin is the most commonly used type of join SELECT a b FROM a INNER JOIN b ON a col one b col two JOIN USING NATURAL JOIN 125 HyperSGL Data Access and Change Joins with USING or NATURAL keywords joins are similar to an equijoin but they cannot be replaced simply with an equijoin The new table is formed with the specified or implied shared columns of the two tables followed by the rest of the columns from each table In NATURAL JOIN the shared columns are all the column pairs that have the same name in the first and second table In JOIN USING only columns names that are specified by the USING clause are shared The joins are expressed as A NATURAL JOIN B andA JOIN B USING comma separated column name list The columns of the joined table are formed by the following procedures In JOIN USING the shared columns are added to the joined table in the same order as they appear in the column name list In NATURAL JOIN the shared columns are added to the joined table in the same order as they appear in the first table In both forms of join the non shared columns of the first table are added in the order they appear in the first table finally the non shared columns of the second table are added in the order they ap
101. for each customer 162 HyperSQL SQL Invoked Routines SELECT ID FIRSTNAME LASTNAME ARRAY AGGREGATE CAST INVOICE TOTAL AS VARCHAR 100 FROM customer JOIN INVOICE ON ID CUSTOMERID GROUP BY ID FIRSTNAME LASTNAME 11 Susanne Karsen ARRAY 3988 20 12 John PetersonmeARRAY 29087 Ow WA 3820 100 aA ORs Or Ba Gee QI 13 Michael Clancy ARRAY 6525 30 14 James King ARRAY ID US 665 40 7 905 EO w498 00 9 18 Sylvia Clancy ARRAY 634 20 4883 10 20 Bob Clancy ARRAY 3414 60 744 60 In the example below the function returns a string that contains the comma separated list of all the values passed for the aggregated column This function is similar to the built in GROUP_CONCAT function CREATE AGGREGATE FUNCTION group_concatenate IN val VARCHAR 100 IN flag BOOLEAN INOUT buffer VARCHAR 1000 INOUT counter INT RETURNS VARCHAR 1000 CONTAINS SQL BEGIN ATOMIC IF FLAG THEN RETURN BUFFER ELSE IF val IS NULL THEN RETURN NULL END IF IF buffer IS NULL THEN SET BUFFER END IF IF counter IS NULL THEN SET COUNTER 0 END IF TE counter gt 0 THEN SET buffer buffer END IF SET buffer buffer val SET counter counter 1 RETURN NULL END IF END The same tables and data as for the previous example is used Part of the output is shown Each row of the output is a comma separated list of names SELECT group concatenate firstname lastname FRO
102. granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Overview Text Table support for HSQLDB was originally developed by Bob Preston independently from the Project Subsequently Bob joined the Project and incorporated this feature into version 1 7 0 with a number of enhancements especially the use of conventional SQL commands for specifying the files used for Text Tables In a nutshell Text Tables are CSV or other delimited files treated as SQL tables Any ordinary CSV or other delimited filecan be used The full range of SQL queries can be performed on these files including SELECT INSERT UPDATE and DELETE Indexes and unique constraints can be set up and foreign key constraints can be used to enforce referential integrity between Text Tables themselves or with conventional tables The delimited file can be created by the engine or an existing file can be used HyperSQL with Text Table support is the only comprehensive solution that employs the power of SQL and the universal reach of JDBC to handle data stored in text files The Implementation Definition of Tables Text Tables are defined similarly to conventional tables with the added TEXT keyword CREATE TEXT TABLE tablename column definition
103. gt is specified the search begins with the position indicated by lt offset gt If the search is not successful 0 is returned Equivalent to SQL Foundation POSITION char value expr 1 IN lt char value expr 2 gt Without the third argument LOCATE is equivalent to the SQL Standard POSITION function JDBC LPAD 174 HyperSGL Built In Functions LPAD char value expr 1 gt length char value expr 2 Returns a character string with the length of lt length gt characters The string contains the characters of char value expr 1 padded to the left with spaces If lt length gt is smaller than the length of the string argument the argument is truncated If the optional char value expr 2 is specified this string is used for padding instead of spaces HyperSQL LTRIM LTRIM char value expr gt Returns a character string based on char value expr gt with the leading space characters removed Equivalent to SQL Foundation TRIM LEADING FROM char value expr JDBC OCTET LENGTH OCTET LENGTH string value expression The OCTET LENGTH function can be used with character or binary strings Return a BIGINT value that measures the length of the string in octets When used with character strings the octet count is returned which is twice the normal length Foundation OVERLAY OVERLAY char value expr 1 PLACING char value expr 2 FROM start pos
104. http hsqldb org doc 2 0 verbatim sample server properties e Local verbatim sample sqltoolrc http hsgldb org doc 2 0 verbatim sample sqltool rc e Local verbatim sample hsgldb init http hsgldb org doc 2 0 verbatim sample hsqldb init 295 HyperSQL SQL Index Symbols _SYSTEM ROLE 88 A ABS function 178 ACOS function 178 ACTION_ID function 196 ADD COLUMN 60 add column identity generator 62 ADD CONSTRAINT 60 ADD DOMAIN CONSTRAINT 64 ADMINISTRABLE_ROLE_AUTHORIZATIONS 75 aggregate function 116 ALL and ANY predicates 113 ALTER COLUMN 61 alter column identity generator 62 alter column nullability 62 ALTER DOMAIN 63 ALTER INDEX 71 ALTER routine 67 ALTER SEQUENCE 69 ALTER SESSION 35 ALTER TABLE 60 ALTER USER SET INITIAL SCHEMA 91 ALTER USER SET LOCAL 91 ALTER USER SET PASSWORD 90 ALTER view 63 APPLICABLE_ROLES 75 ASCII function 173 ASIN function 178 ASSERTIONS 75 ATAN2 function 178 ATAN function 178 AUTHORIZATION IDENTIFIER 88 AUTHORIZATIONS 75 BACKUP DATABASE 210 BETWEEN predicate 112 binary literal 101 BINARY types 15 BIT_LENGTH function 173 BITAND function 178 BITANDNOT function 178 bit literal 101 BITNOT function 179 BITOR function 179 BIT types 15 BITXOR function 179 boolean literal 102 BOOLEAN types 13 boolean value expression 110 C CARDINALITY function 190 CASCADE or RESTRICT 50 case expression 10
105. if either Transaction A or B attempts to insert a row it will have to be terminated as the other transaction holds a shared lock on the table If instead of two operations a single MERGE statement is used to perform the read and write no contention occurs because both locks are obtained at the same time Alternatively there is the option of obtaining the necessary locks with an explicit LOCK TABLE statement This statement should be executed before other statements and should include the names of all the tables and the locks needed After this statement all the other statements in the transaction can be executed and the transaction committed The commit will remove all the locks HyperSQL detects deadlocks before attempting to execute a statement When a lock is released after the completion of the statement the first transaction that is waiting for the lock is allowed to continue HyperSQL is fully multi threaded It therefore allows different transactions to execute concurrently so long as they are not waiting to lock the same table for write Locks in SQL Routines and Triggers In both LOCKS and MVLOCKS models SQL routines functions and procedures and triggers obtain all the read and write locks at the beginning of the routine execution SQL statements contained in the routine or trigger are all executed without deadlock as all the locks have already been obtained At the end of execution of the routine or trigger read locks are released
106. if the session isolation level is READ COMMITTED MVCC In the MVCC model there are no shared read locks Exclusive locks are used on individual rows but their use is different Transactions can read and modify the same table simultaneously generally without waiting for other transactions The SQL Standard isolation levels are used by the user s application but these isolation levels are translated to the MVCC isolation levels READ CONSISTENCY or SNAPSHOT ISOLATION When transactions are running at READ COMMITTED level no conflict will normally occur If a transaction that runs at this level wants to modify a row that has been modified by another uncommitted transaction then the engine puts the transaction in wait until the other transaction has committed The transaction then continues automatically This isolation level is called READ CONSISTENCY 33 HyperSGL Sessions and Transactions Deadlock is completely avoided In theory conflict is possible if each transaction is waiting for a different row modified by the other transaction In this case one of the transactions is immediately terminated rolled back unless the setting has been changed with the set database transaction rollback on conflict statement When this setting is changed to FALSE the session that avoided executing the deadlock causing statement returns an error but without rolling back the previous actions This will cause the other transaction to wait for the c
107. in progress If SQL Data is modified during a transaction the change can be undone with a ROLLBACK statement When a COMMIT statement is executed the transaction is ended If a single statement fails the transaction is not normally terminated However some failures are caused by execution of statements that are in conflict with statements executed in other concurrent sessions Such failures result in an implicit ROLLBACK in addition to the exception that is raised Schema definition and manipulation statements are also transactional according to the SQL Standard HyperSQL 2 0 performs automatic commits before and after the execution of such transactions Therefore schema related statements cannot be rolled back This is likely to change in future versions Some statements are not transactional Most of these statements are used to change the properties of the session These statements begin with the SET keyword If the AUTOCOMMIT property of a session is TRUE then each transactional statement is followed by an implicit COMMIT The default isolation level for a session is READ COMMITTED This can be changed using the JDBC java sql Connection object and its setTransactionIsolation int level method The session can be put in read only mode using the setReadOnly boolean readOnly method Both methods can be invoked only after a commit or a rollback but not during a transaction The isolation level and or the readonly mode of a transaction
108. in unexpected results For example the expression BETWEEN TIME 12 00 00 8 00 TIME 22 00 00 8 005 is converted to BETWEEN TIME 20 00 00 0 00 TIME 06 00 004 0 00 when it is evaluated in the UTC zone which is always FALSE Functions Several functions return the current session timestamp in different datetime types CURRENT DATE DATE CURRENT TIME TIME WITH TIME ZONE CURRENT TIMESTAMP TIMESTAMP WITH TIME ZONE LOCALTIME TIMESTAMP WITHOUT TIME ZONE LOCALTIMESTAMP TIMESTAMP WITHOUT TIME ZONE Session Time Zone Displacement When an SQL session is started with a JDBC connection the local time zone of the client JVM including any seasonal time adjustments such as daylight saving time is used as the session time zone displacement Note that the SQL session time displacement is not changed when a seasonal time adjustment takes place while the session is open To change the SQL session time zone displacement use the following commands SET TIME ZONE lt time displacement gt SET TIME ZONE LOCAL The first command sets the displacement to the given value The second command restores the original real time zone displacement of the session Datetime Values and Java When datetime values are sent to the database using the PreparedStatement or CallableStatement interfaces the Java object is converted to the type of the prepared or callable statement parameter This type may be DATE TIME or TIMESTAMP with o
109. inserted into a table by the current session Each session manages this function call separately and is not affected by inserts in other sessions The statement can be executed as a direct statement or a prepared statement HyperSQL DATABASE DATABASE Returns the file name without directory information of the database JDBC DATABASE NAME DATABASE NAME Returns the database name This name is a 16 character uppercase string It is generated as a string based on the timestamp of the creation of the database for example HSQLDB32438AEAFB The name can be redefined by an admin user but the new name must be all uppercase and 16 characters long This name is used in log messages with external logging frameworks HyperSQL DATABASE VERSION DATABASE VERSION Returns the full version string for the database engine For example 2 0 1 JDBC USER USER Equivalent to the SQL function CURRENT USER JDBC CURRENT USER CURRENT USER CURRENT ROLE CURRENT ROLE 194 HyperSGL Built In Functions SESSION USER SESSION USER SYSTEM USER SYSTEM USER CURRENT SCHEMA CURRENT SCHEMA CURRENT CATALOG CURRENT CATALOG These functions return the named current session attribute They are all SQL Standard functions The CURRENT USER is the user that connected to the database or a user subsequently set by the SET AUTHORIZATION statemen
110. is larger than 1 The rules are If all fields are null X IS NULL is TRUE and X IS NOT NULL is FALSE If only some fields are null both X IS NULLand X IS NOT NULL are FALSE If all fields are not null X IS NULLis FALSE and X IS NOT NULL is TRUE ALL and ANY 113 HyperSGL Data Access and Change quantified comparison predicate quantified comparison predicate row value predicand comp op quantifier table subquery lt quantifier gt all some all ALL some SOME ANY Specify a quantified comparison For a quantified comparison the lt row value predicand gt is compared one by one with each row of the lt table sub query gt If the lt table subquery gt returns no rows then if ALL is specified the result is TRUE but if SOME or ANY is specified the result is FALSE If ALL is specified if the comparison is TRUE for all rows the result of the predicate is TRUE If the comparison is FALSE for at least one row the result is FALSE Otherwise the result is UNKNOWN If SOME or ANY is specified if the comparison is TRUE for at least one row the result is TRUE If the comparison is FALSE for all rows the result is FALSE Otherwise the result is UNKNOWN Note that the IN predicate is equivalent to the SOME or ANY predicate using the lt equals operator gt In the examples below the date of an invoice is compared to holidays in a given year In the first example the
111. isused data type must be specified A generated column can be part of a foreign key or unique constraints or a column of an index This capability is the main reason for using generated columns A generated column may contain a formula that computes a value based on the values of other columns Fast searches of the computed value can be performed when an index is declared on 54 HyperSGL Schemas and Database Objects the generated column Or the computed values can be declared to be unique using a UNIQUE constraint on the table The computed column cannot be overridden by user supplied values When a row is updated and the column values change the generated columns are computed with the new values When a row is inserted into a table or an existing row is updated no value except DEFAULT can be specified for a generated column In the example below data is inserted into the non generated columns and the generated column will contain Felix the Cat or Pink Panther CREATE TABLE t id INTEGER PRIMARY KEY firstname VARCHAR 20 lastname VARCHAR 20 fullname VARCHAR 40 GENERATED ALWAYS AS firstname lastname INSERT INTO t id firstname lastname VALUES 1 Felix the Cat INSERT INTO t id firstname lastname fullname VALUES 2 Pink Panther DEFAULT DEFAULT default clause A default clause can be used if GENERATED is not specified If a column has a default clause then it is po
112. java text SimpleDateFormat format string Separator characters space comma period hyphen colon semicolon forward slash can be included between the pattern elements Unsupported format strings should not be used You can include a string literal inside the format string by enclosing it in double quotes see the second example above HyperSQL TO DATE TO DATE char value expr gt char value expr gt This function translates a formatted datetime sting to a TIMESTAMP O according to the format given in the second argument See TO TIMESTAMP below for further details TO TIMESTAMP TO TIMESTAMP char value expr char value expr gt This function translates a formatted datetime sting to a TIMESTAMP 6 according to the format given in the second argument The format string can contain pattern elements from the list given below plus punctuation and space characters The pattern should contain all the necessary fields to construct a date including year month day of month etc The returned timestamp can then be cast into DATE or TIME types if necessary An example including the result is given below TO TIMESTAMP 22 11 2008 20 30 40 DD MM YYYY HH MI SS TIMESTAMP 2008 11 22 20 30 40 000000 The format strings that can be used for TO DATE and TO_TIMESTAMP are more restrictive than those used for TO_CHAR because the format string must contain the elements needed to build a full DATE or TI
113. jsse JSSERefGuide html CreateKeystore Automatic Server or WebServer startup on UNIX If you are on UNIX and want to automatically start and stop a Server or WebServer running with encryption set the system javax net ssl keyStore and system javax net ssl keyStorePassword properties as instructed above and follow the instructions in the HyperSQL on UNIX chapter paying close attention to the TLS related comments in the template config file If you are using a private server certificate make sure to also set the trust store filepath for relevant urlids in your RC file as explained in the sample config file Network Access Control Server ACLs JDBC connections will always be denied if the supplied user and password are not found in the target catalog But an HyperSQL listener can also restrict access at the listener level even protecting private catalogs which have insecure or default passwords If you have an in process setup this section of the Guide doesn t apply to you Many in fact most distributed database applications don t have application clients connect directly to the database but instead encapsulate access in a controlling process For example a web app will usually access the data source on behalf of users with end user web browsers never accessing the database directly In these cases and others the security benefits of restricting listener access to specific source addresses is well worth the effort ACLs work by r
114. new value is generated by the sequence generator by adding the increment to the last value it generated In the example below the expression is used in an insert statement INSERT INTO MYTABLE COL1 COL2 VALUES 2 NEXT VALUE FOR MYSEQUENCE CURRENT VALUE FOR current value expression lt current value expression gt CURRENT VALUE FOR lt sequence generator name gt Return the latest value that was returned by the NEXT VALUE FOR expression for a sequence generator In the example below the value that was generated by the sequence for the first insert is reused for the second insert INSERT INTO MYTABLE COL1 COL2 VALUES 2 NEXT VALUE FOR MYSEQUENCE INSERT INTO CHILDTABLE COL1 COL2 VALUES 10 CURRENT VALUE FOR MYSEQUENCE value expression value expression lt value expression gt lt numeric value expression gt lt string value expression gt lt datetime valu xpression gt lt interval value expression gt lt boolean value expression gt lt row value expression gt An expression that returns a value The value can be a single value or a row consisting more than one value numeric value expression numeric value expression lt numeric value expression gt lt term gt lt numeric value expression gt lt plus sign gt lt term gt lt numeric value expression gt lt minus sign gt lt term gt lt term gt lt factor gt lt term gt lt asterisk gt lt factor g
115. only supports Java methods within the classpath The external Java reference string is a quoted string which starts with CLASSPATH and is followed by the Java package class and method names separated with dots HyperSQL does not currently support the optional Java parameter declaration list external body reference EXTERNAL NAME external Java reference string external Java reference string jar and class name period Java method name Java parameter declaration list Routine Characteristics The routine characteristics clause covers several sub clauses routine characteristics routine characteristic routine characteristic language clause lt parameter style clause SPECIFIC specific name deterministic characteristic SQL data access indication lt null call clause returned result sets characteristic savepoint level indication LANGUAGE language clause The language clause refers to the language in which the routine body is written It is either SQL or Java The default is SQL so JAVA must be specified for SQL JRT routines 2 lt language clause gt LANGUAGE lt language name gt lt language name gt SQL JAVA The parameter style is not allowed for SQL routines It is optional for Java routines and in HyperSQL the only value allowed is JAVA lt parameter style gt
116. or gradle bat command repeatedly with different switches and arguments Note Gradle s v switch reports version details more directly than the explainjars task does from the operating system version to the Groovy version the language interpreter used for Gradle instructions 286 HyperSQL Building HyperSQL Jars iii the Gradle GUI fo Gradle amp 6 x explainjars List it erntian of jars that you can build explainprops Explain how to change default build properties ext validation setup Set up a capable standalone XML validator fetch images Fetch stock DocBook image files from Internet fetch jflex Fetch JFlex jar file from Internet for rebuilsing SqlTool scanner gen docs Generate Docbook documents for project help Displays a help message hsqldb Build the default hsqldb jar hsqldbmain Build the hsqldbmain jar no utilities hsqldbmin Build the hsqldbmin jar no connection pooling or servers hsqldbtest Build the hsqldbtest jar default plus test classes hsqldbutil Build the utility hsqldbutil jar hsqljdbc Build the hsgljdbc jar for network clients javadoc Create javadoc for the distribution package javadocdev Create javadoc for all HSQLDB code base classes jflex Execute JFlex For SglTool scanner developers lib compiles the JVM independent lib classes nichts Noop for testing Gradle Execute help x 9 Completed successfully at 1 20 47 AM Executing command help help Welcome to Grad
117. own jar file with Java 1 3 make sure to install JSSE first Encrypting your JDBC connection At this time only 1 way server cert encryption is tested Client Side Just use one of the following protocol prefixes Hsqldb TLS URL Prefixes jdbc hsqldb hsqls jdbc hsqldb https At this time the latter will only work for clients running with Java 1 4 or later If the listener you wish to connect to is using a certificate approved by your default trust keystore then there is nothing else to do If not then you need to tell Java to trust the server cert It s a slight over simplification to say that if 247 HyperSGL HyperSQL Network Listeners Servers the server certificate was purchased then you are all set if somebody signed their own certificate by self signing or using a private ca certificate then you need to set up trust First you need to obtain the cert only the public part of it Since this cert is passed to all clients you could obtain it by writing a Java client that dumps it to file or perhaps by using openssl s client Since in most cases if you want to trust a non commercial cert you probably have access to the server keystore I ll show an example of how to get what you need from the server side JKS keystore You may already have an X509 cert for your server If you have a server keystore then you can generate a X509 cert like this Example 13 1 Exporting certificate from the serve
118. query expression DO SQL statement list END FOR ending label The query expression is a SELECT statement When the FOR statement is executed the query expression is executed first and the result set is formed Then for each row of the result set the SOL statement list is executed What is special about the FOR statement is that all the columns of the current row can be accessed by name in the statements in the SOL statement list The columns are read only and cannot be updated For example if the column names for the select statement are ID FIRSTNAME LASTNAME then these can be accessed as a variable name The column names must be unique and not equivalent to any parameter or variable name in scope The FOR statement is useful for computing values over multiple rows of the result set or for calling a procedure for some row of the result set In the example below the procedure uses a FOR statement to iterate over the rows for a customer with lastname equal to name p No action is performed for the first row but for all the subsequent rows the row is deleted from the table Note the following The result set for the SELECT statement is built only once before processing the statements inside the FOR block begins For all the rows of the SELECT statement apart from the first row the row is deleted from the customer table The WHERE condition uses the automatic variable id which holds the customer id value for the cu
119. read only or the isolation modes Choosing the Transaction Model The SQL Standard defines the isolation levels as modes of operation that avoid the three unwanted phenomena dirty read fuzzy read and phantom row The dirty read phenomenon occurs when a session can read a row that has been changed by another session The fuzzy read phenomenon occurs when a row that was read by a session is modified by another session then the first session reads the row again The phantom row phenomenon occurs when a session performs an operation that affects several rows for example counts the rows or modifies them using a search condition then another session adds one or more rows that fulfil the same search condition then the first session performs an operation that relies on the results of its last operation According to the Standard the SERIALIZABLE isolation level avoids all three phenomena and also ensures that all the changes performed during a transaction can be considered as a series of uninterrupted changes to the database without any other transaction changing the database at all for the duration of these actions The changes made by other transactions are considered to occur before the SERIALIZABLE transaction starts or after it ends The READ COMMITTED level avoids dirty read only while the REPEATABLE READ level avoids dirty read and fuzzy read but not phantom row The Standard allows the engine to return a higher isolation leve
120. required for column naming The expression A AS X comma separated column name list means table A is used in the query expression as table X and its columns are named as in the given list The original name A or its original column names are not visible in the scope of the query The BNF is given below The correlation name can be the same or different from the name of the table The derived column list isacomma separated list of column names The degree of this list must be equal to the degree of the table The column names in the list must be distinct They can be the same or different from the names of the table s columns table or query name AS correlation name left paren derived column list right paren In the examples below the columns of the original tables are named a b c d e f The two queries are equivalent In the second query the table and its columns are renamed and the new names are used in the WHERE clauses CREATE TABLE atable a INT INT c INI d INT INI E IND SELECT d e f FROM atable WHERE a b c SELECT x y Z FROM akable AS t u Vy w Yr Z WHERE u v w Naming in Select List Naming in the SELECT list logically takes place after naming in the joined table The new names for columns are not visible in the immediate query expression or query expression They become visible in the ORDER BY clause and in the result table that is returned to the us
121. routine SQL invoked routine SQL invoked routine schema routine schema routine schema procedure schema function schema procedure CREATE SOL invoked procedure lt schema function gt CREATE lt SQL invoked function gt lt SQL invoked procedure PROCEDURE schema qualified routine name SQL parameter declaration list routine characteristics routine body SOL invoked function function specification method specification designator routine body SQL parameter declaration list left paren SQL parameter declaration comma SQL parameter declaration right paren SQL parameter declaration parameter mode SQL parameter name parameter type RESULT lt parameter mode IN OUT INOUT lt parameter type data type function specification FUNCTION schema qualified routine name SQL parameter declaration list returns clause routine characteristics dispatch clause method specification designator SPECIFIC METHOD specific method name INSTANCE STATIC CONSTRUCTOR METHOD method name SQL parameter declaration list returns clause FOR schema resolved user defined typ name routine characteristics routine characteristic 66 HyperSGL
122. sample sqltool rc tothe HSQLDB_OWNER s home directory Use chmod to make the file readable and writable only to HSQLDB OWNER old ssqitoollinre 4313 20110606 02 o 3 87 unsaved This is a sample RC configuration file used by SqlTool DatabaseManager and any other program that uses the org hsqldb lib RCData class See the documentation for SqlTool for various ways to use this file If you have the least concerns about security then secure access to your KC file You can run SqglTool right now by copying this file to your home directory and running java jar path to sqltool jar mem This will access the first urlid definition below in order to use a personal Memory Only database url values may of course contain JDBC connection properties delimited with semicolons As of revision 3347 of SqlFile you can also connect to datasources defined here from within an SqlTool session file with the command Vj urlid You can use Java system property values in this file like this S user home The only feature added recently is the optional transiso setting which may be set to an all caps transaction isolation level as listed in the Java API Spec for java sql Connection Windows users are advised to use forward slashes instead of reverse slashes and to avoid paths containing spaces or other funny characters This recommendation applies to any Java app not just SqlTool A personal Memory Only non persistent database
123. sequence the value returned from this table by one session could also be used by a different session causing a sequence value to be used twice unintentionally Identity Auto Increment Columns Each table can contain a single auto increment column known as the IDENTITY column An IDENTITY column is a SMALLINT INTEGER BIGINT DECIMAL or NUMERIC column with its value generated by a sequence generator In HyperSQL 2 0 an IDENTITY column is not by default treated as the primary key for the table as a result multi column primary keys are possible with an IDENTITY column present The SQL standard syntax is used which allows the initial value and other options to be specified colname INTEGER BIGINT DECIMAL NUMERIC GENERATED BY DEFAULT ALWAYS AS IDENTITY soper ns N When you add a new row to such a table using an INSERT INTO tablename statement you can use the DEFAULT keyword for the IDENTITY column which results in an auto generated value for the column 45 HyperSGL Schemas and Database Objects The IDENTITY function returns the last value inserted into any IDENTITY column by this session Each session manages this function call separately and is not affected by inserts in other sessions Use CALL IDENTITY as an SQL statement to retrieve this value If you want to use the value for a field in a child table you can use INSERT INTO childtable VALUES IDENTITY Both ty
124. session settings and should not include statements that create or alter tables or other database objects These rules are generally enforced by the engine but additional enforcement may be added in future versions An example of a procedure definition together with its Java signature is given below This procedure is the SQL JRT version of the example discussed above for SQL PSM CREATE PROCEDURE get customer IN id INT OUT firstname VARCHAR 50 OUT lastname VARCHAR 50 READS SQL DATA LANGUAGE JAVA EXTERNAL NAME CLASSPATH org hsqldb test TestOl getCustomerProcedure public static void getCustomerProcedure int id String firstn String lastn throws java sql SQLException firstn 0 somevalue 158 HyperSQL SQL Invoked Routines lastn 0 somevalue In the next example a procedure is defined to return a result set The signature of the Java method is also given The Java method assigns a ResultSet object to the zero element of the result parameter CREATE PROCEDURE new customer firstname VARCHAR 50 lastname VARCHAR 50 MODIFIES SOL DATA LANGUAGE JAVA DYNAMIC RESULT SETS 1 EXTERNAL NAME CLASSPATH org hsqldb test Test01 newCustomerProcedure public static void newCustomerProcedure String firstn String lastn String addr ResultSet result throws java sql SQLException result 0 someresultset Java language procedures SQL JRT are used in an identical manner to SQL PSM routines See th
125. some table or column names that are SQL reserved keywords without double quoting Version 2 0 does not accept unquoted table or column names which begin with an underscore unless the connection sql regular names is set false Version 2 0 is more strict with check conditions and default values Other manual changes are also possible Note that the script file must be the result of a SHUTDOWN SCRIPT and must contain the full data for the database The following changes can be applied so long as they do not affect the integrity of existing data Names Names of tables columns and indexes can be changed These changes must be consistent regarding foreign key constraint references CHECK A check constraint can always be removed NOT NULL A not null constraint can always be removed PRIMARY KEY A primary key constraint can be removed It cannot be removed if there is a foreign key referencing the column s e UNIQUE A UNIQUE constraint can be removed if there is no foreign key referencing the column s e FOREIGN KEY A FOREIGN KEY constraint can always be removed COLUMN TYPES Some changes to column types are possible For example an INTEGER column can be changed to BIGINT After completing the changes and saving the modified script file you can open the database as normal Backward Compatibility Issues HyperSQL 2 0 conforms to the SQL Standard better than previous versions and has many more features For these
126. specific to version 1 5 and later ant switchtojdk14 ant hsqldb translate the jar Building with IDE Compilers All HyperSQL source files are supplied ready to compile There is no complex pre compile stage It is therefore possible to compile the sources with an IDE without using Gradle or Ant Only if compilation with Java 1 5 is required 289 HyperSGL Building HyperSQL Jars you should first run the Gradle task or Ant target before compiling and remove from the source directories a few source files that are specific to Java 6 these are listed in the build xml file Hsqldb CodeSwitcher CodeSwitcher is a tool to manage different version of Java source code It allows to compile HyperSQL for different JDKs It is something like a precompiler in C but it works directly on the source code and does not create intermediate output or extra files CodeS witcher is used internally in the Ant build You do not have to invoke it separately to compile HyperSQL CodeSwitcher reads the source code of a file removes comments where appropriate and comments out the blocks that are not used for a particular version of the file This operation is done for all files of a defined directory and all subdirectories Example B 2 Example source code before CodeSwitcher is run tifdef JAVA2 properties store out hsqldb database else properties save out hsqldb database D endif The ne
127. string seperated into parts a string s literal form with quote character U amp Unicode string with Greek delta NO394 and phi 03a6 letters binary literal binary literal binary string literal X quote space hexit space lt hexit gt space quote separator quote space lt hexit gt space hexit space quote hexit digit A B C D E F a lbi ci ad e f The type of a binary literal is BINARY The octet length of the binary literal is the length of the type Case insensitive hexadecimal characters are used in the binary string Each pair of characters in the literal represents a byte in the binary string Long literals can be divided into multiple quoted strings separated with a space or end of line character X labACD34 Af bit literal bit literal bit string literal B quote bit quote separator quote bit quote bit 0 1 The type of a binary literal is BIT The bit length of the bit literal is the length of the type Digits O and 1 are used to represent the bits Long literals can be divided into multiple quoted strings separated with a space or end of line character T3150 018009120 OQ ORO numeric literal numeric literal signed numeric literal sign unsigned num
128. such as synchronization with another data source All concurrency models are very fast in operation When data change operations are mainly on the same tables the MVCC model may be faster especially with multi core processors Schema and Database Change There are a few SQL statements that must access a consistent state of the database during their executions These statements which include CHECKPOINT and BACKUP put an exclusive lock on all the tables of the database when they start Some schema manipulation statements put an exclusive lock on one or more tables For example changing the columns of a table locks the table exclusively In the MVCC model all statements that need an exclusive lock on one or more tables put an exclusive lock on the database catalog until they complete The effect of these exclusive locks is similar to the execution of data manipulation statements with write locks The session that is about to execute the schema change statement waits until no other session is holding a lock on any of the objects At this point it starts its operation and locks the objects to prevents any other session from accessing the locked objects As soon as the operation is complete the locks are all removed Simultaneous Access to Tables It was mentioned that there is no limit on the number of sessions that can access the tables and all sessions work simultaneously in multi threaded execution However there are internal resources th
129. target column otherwise an error is returned For example when 1234567890123456789012 12345687901234567890 is evaluated the result can be stored in any integral type column even a TINYINT column as it is a small value In SQL Statements an integer literal is treated as INTEGER unless its value does not fit In this case it is treated as BIGINT or DECIMAL depending on the value Depending on the types of the operands the result of the operations is returned in a JDBC ResultSet in any of related Java types Integer Long or BigDecimal The ResultSet getXXXX methods can be used to retrieve the values so long as the returned value can be represented by the resulting type This type is deterministically based on the query not on the actual rows returned Other Numeric Types In SQL statements number literals with a decimal point are treated as DECIMAL unless they are written with an exponent Thus 0 2 is considered a DECIMAL value but 0 2E0 is considered a DOUBLE value When an approximate numeric type REAL FLOAT or DOUBLE all synonymous is part of an expression involving different numeric types the type of the result is DOUBLE DECIMAL values can be converted to DOUBLE unless 12 HyperSGL SQL Language they are beyond the Double MIN VALUE Double MAX VALUE range For example A B A B A B etc will return a DOUBLE value if either A or B is a DOUBLE Otherwise when no DOUBLE value exists if a DE
130. temporary tables The GLOBAL TEMPORARY type is a schema object It is created with the CREATE GLOBAL TEMPORARY TABLE statement The definition of the table persists and each session has access to the table But each session sees its own copy of the table which is empty at the beginning of the session The LOCAL TEMPORARY type is not a schema object It is created with the DECLARE LOCAL TEMPORARY TABLE statement The table definition lasts only for the duration of the session and is not persisted in the database The table can be declared in the middle of a transaction without committing the transaction When the session commits the contents of all temporary tables are cleared by default If the table definition statements includes ON COMMIT PRESERVE ROWS then the contents are kept when a commit takes place The rows in temporary tables are stored in memory by default If the hsqldb result max memory rows SET SESSION RESULT MEMORY ROWS row count has been specified tables with row count above the setting are stored on disk Persistent Tables HyperSQL supports the Standard definition of persistent base table but defines three types according to the way the data 1s stored These are MEMORY tables CACHED tables and TEXT tables Memory tables are the default type when the CREATE TABLE command is used Their data is held entirely in memory but any change to their structure or contents is written to the
131. tested for equality with 22 or 23 and if the test evaluates to TRUE then the INSERT statement is performed and the statement ends If the test does not evaluate to TRUE the next condition test which is an IN predicate is performed with var_one and so on The statement after the ELSE clause is performed if none the previous tests returns TRUE CASE var_one WHEN 22 23 THEN INSERT INTO t one WHEN IN 2 4 5 THEN DELETE FROM t_one WHERE ELSE UPDATE t_one END CASE The searched case statement uses one or more search conditions and for each search condition it specifies one or more SQL statements to execute if the search condition evaluates TRUE An exception is raised if there is no ELSE clause and none of the search conditions evaluates TRUE lt searched cas statement gt CASE lt searched case statement when clause gt lt case statement else clause gt END CASE lt searched cas statement when clause gt WHEN lt search condition gt THEN lt SQL statement list gt The example below is partly a rewrite of the previous example but a new condition is added CASE WHEN var_one 22 OR var_one 23 THEN INSERT INTO t_one WHEN var_one IN 2 4 5 THEN DELETE FROM t_one WHERE WHEN var_two IS NULL THEN UPDATE t_one ELSE UPDATE CONS en END CASE IF if statement The if statement is very similar to the searched case statement The difference is that no exceptio
132. that prevents triggered data change exceptions caused by multiple ON UPDATE or ON DELETE SET clauses of foreign key constraint When there are multiple constraints a field in a row may be updated by two constraints to different values in the same operation This is not allowed by default Changing this to FALSE allows such violations of the Standard to pass without an exception The property is TRUE by default SQL Standard requires enforcement therefore this property shouldn t be changed unless an application written for a non conforming RDBMS needs it Only a user with the DBA role can execute this statement This is equivalent to the connection property sql enforce tdc update SET DATABASE SQL TRANSLATE TTI TYPES set database sql translate tti types statement lt set database sql translate tti types statement gt SET DATABASE SQL TRANSLATE TTI TYPES TRUE FALSE The JDBC Specification up to version 4 1 does not support some SQL Standard built in types therefore these types must be translated to a supported type when accessed through JDBC ResultSet and PreparedStatement methods If the property is true the TIME TIMESTAMP WITH TIME ZONE types and INTERVAL types are represented in JDBC methods of Result SetMetaData and DatabaseMetaData as JDBC datetime types without time zone and the VARCHAR type respectively The original type names are preserved The property is TRUE by default If set to FALSE
133. the generated value DROP COLUMN drop column definition drop column definition DROP COLUMN column name drop behavior Destroy a column of a base table The drop behavior is either RESTRICT or CASCADE If the column is referenced in a table constraint that references other columns as well as this column or if the column is referenced in a VIEW or the column is referenced in a TRIGGER then the statement will fail if RESTRICT is specified If CASCADE is specified then any CONSTRAINT VIEW or TRIGGER object that references the column is dropped with a cascading effect ADD CONSTRAINT add table constraint definition add table constraint definition ADD table constraint definition 60 HyperSGL Schemas and Database Objects Add a constraint to a table The existing rows of the table must conform to the added constraint otherwise the statement will not succeed DROP CONSTRAINT drop table constraint definition drop table constraint definition DROP CONSTRAINT constraint name drop behavior Destroy a constraint on a table The drop behavior has an effect only on UNIQUE and PRIMARY KEY constraints If such a constraint is referenced by a FOREIGN KEY constraint the FOREIGN KEY constraint will be dropped if CASCADE is specified If the columns of such a constraint are used in a GROUP BY clause in the query expression of a VIEW or another kind of schema object and a functi
134. the database and then performing a simple SHUTDOWN After upgrading a database you may want to change some of its settings For example the new SET FILES BACKUP INCREMENT TRUE statement can improve the shutdown and checkpoint times of larger databases Once a database is upgraded to 2 0 it can no longer be used with previous versions of HyperSQL Upgrading From Older Versions To upgrade from version 1 8 x with the default TEXT format script files follow the instructions above If the 1 8 x files have database script format set to BINARY or COMPRESSED ZIPPED you must issue the SET SCRIPTFORMAT TEXT and SHUTDOWN SCRIPT commands with the old version then open with the new version of the engine In most cases the upgrade is successful and complete It is strongly recommended to execute SHUTDOWN COMPACT after an automatic upgrade from previous versions If your database has been created with version 1 7 2 or 1 7 3 first upgrade to version 1 8 1 and performa SHUTDOWN SCRIPT with this version You can then upgrade the database to version 2 0 To upgrade from older version database files 1 7 1 and older that contain CACHED tables use the SCRIPT procedure below In all versions of HyperSQL the SCRIPT filename command used as an SQL statement allows you to save a full record of your database including database object definitions and data to a file of your choice You can export a script file using the old version of the database engine an
135. the deleted or inserted rows For UPDATE actions there is both an old and new version of each row A trigger can be specified to activate before or after the action has been performed BEFORE Triggers A trigger that is declared as BEFORE DELETE cannot modify the deleted row In other words it cannot decide to delete a different row by changing the column values of the row A trigger that is declared as BEFORE INSERT and BEFORE UPDATE can modify the values that are inserted into the database For example a badly formatted string can be cleaned up by a trigger before INSERT or UPDATE BEFORE triggers cannot modify the other tables of the database All BEFORE triggers can veto the action by throwing an exception Because BEFORE triggers can modify the inserted or updated rows all constraint checks are performed after the execution of the BEFORE triggers The checks include NOT NULL constraints length of strings CHECK constraints and FOREIGN key constraints 165 HyperSGL Triggers AFTER Triggers AFTER triggers can also perform additional data changes for example inserting an additional row into a different table for data audits These triggers cannot modify the rows that have been modified by the INSERT or UPDATE action INSTEAD OF Triggers A trigger that is declared on a VIEW is an INSTEAD OF trigger This term means when an INSERT UPDATE or DELETE statement is executed with the view as the target the trigger action is all t
136. the file server properties or webserver properties resides SERVER_HOME opt hsqldb 2 0 0 hsqldb data What UNIX user the server will run as The shutdown client is always run as root or the invoker of the init script Runs as root by default but you should take the time to set database file ownerships to another user and set that user name here HSOLDB OWNER hsqldb The HSQLDB jar file specified in HSQLDB JAR PATH above will automatically be in the class path This arg specifies additional classpath elements To embed your own application add your jar file s or class base directories here and add your main class to the INVOC ADDL ARGS setting below Another common use case for adding to your class path is to make classes available to the DB engines for SQL JRT functions and procedures aE db db db db dk 261 HyperSGL HyperSQL on UNIX SERVER ADDL CLASSPATH usr local dist currencybank jar For startup or shutdown failures you can save a lot of debugging time by temporarily adjusting down MAX START SECS and MAX TERMINATE SECS to a little over what it should take for successful startup and shutdown on f your system We require all Server WebServer instances to be accessible within 4 SMAX START SECS from when the Server WebServer is started Defaults to 60 Raise this is you are running lots of DB instances or have a slow server MAX START SECS 200 Max time to allow for JVM to
137. the source fileis ASCII by default To support UNICODE or source files prepared with different encodings this can be changed to UTF 8 or any other encoding The default is encoding ASCII and the option encoding UTF 8 or other supported encodings can be used Finally HSQLDB provides the ability to read a text file as READ ONLY by placing the keyword DESC at the end of the SET TABLE SOURCE statement SET TABLE mytable SOURCE myfile DESC Text table source files are cached in memory The maximum number of rows of data that are in memory at any time is controlled by the cache rows property The default value for cache rows is 1000 and can be changed by setting the default database property The cache size property sets the maximum amount of memory used for each text table The default is 100 KB The properties can be set for individual text tables These properties do not control the maximum size of each text table which can be much larger An example is given below SET TABLE mytable SOURCE myfile ignore first true all quoted true cache rows 10000 cache size 1000 The properties used in earlier versions namely the textdb cache scale and the textdb cache size scale can still be used Disconnecting Text Tables Text tables may be disconnected from their underlying data source i e the text file You can explicitly disconnect a text table from its file by issuing the following statement SET TABLE mytable SOURCE
138. the specified name Set the path to want relative paths will be relative to the directory containing the properties file You can read specify other catalogs of various types and how to make settings for the listen port and many o other chapters of this guide whatever you about how to ther things in 3 Set and export the environmental variable CLASSPATH to the value of HSOLDB_HOME as described above plus lib hsqldb jar like export CLASSPATH CLASSPATH path to hsqldb lib hsqldb jar In HSQLDB_OWNER s home directory run nohup java org hsqldb server Server amp This will start the Listener process in the background and will create your new database catalog dbO Continue on when you see the message containing HSOLDB server is online nohup just make command will not quit when you exit the current shell omit it if that s what you want to do Accessing your Database s sure that the We re going to use SqlTool to access the database so you will need the file sqltool jar in addition to hsqldb jar M sqltool jar isn t already sitting there beside hsqldb jar they both come pre built build it exactly as you would build hsqldb jar except use ant target sqltool If your distribution came with a sqltool 255 HyperSQL HyperSQL on UNIX jar file with a version label like sqltool 1 2 3 4 jar that s fine use that file whenever I say sqltool jar below Copy the file
139. they return much faster when an index exists As a rule of thumb HSQLDB is capable of internal processing of queries at over 100 000 rows per second Any query that runs into several seconds is clearly accessing thousands of rows The query should be checked and indexes should be added to the relevant columns of the tables if necessary The EXPLAIN PLAN FOR query statement can be used to see which indexes are used to process the query When executing a DELETE or UPDATE statement the engine needs to find the rows that are to be deleted or updated If there is an index on one of the columns in the WHERE clause it is often possible to start directly from the first candidate row Otherwise all the rows of the table have to be examined Indexes are even more important in joins between multiple tables SELECT FROM ti JOIN t2 ON tl cl t2 c2 is performed by taking rows of t1 one by one and finding a matching row in t2 If there is no index on t2 c2 then for each row of t1 all the rows of t2 must be checked Whereas with an index a matching row can be found in a fraction of the time If the query also has a condition on tl e g SELECT FROM ti JOIN t2 ON tl cl t2 c2 WHERE ti c3 4 then an index on t1 c3 would eliminate the need for checking all the rows of t1 one by one and will reduce query time to less than a millisecond per returned row So if t1 and t2 each contain 10 000 rows the query without indexes involves checking 100 00
140. value expr gt Returns a character string based on lt char value expr gt with characters in the reverse order HyperSQL RIGHT RIGHT lt char value expr gt lt count gt Returns a character string consisting of the last count characters of char value expr gt JDBC RPAD RPAD lt char value expr 1 gt lt length gt lt char value expr 2 gt Returns a character string with the length of lt length gt characters The string begins with the characters of char value expr 1 padded to the right with spaces If lt length gt is smaller than the length of the string argument the argument is truncated If the optional lt char value expr 2 gt is specified this string is used for padding instead of spaces HyperSQL RTRIM 176 HyperSGL Built In Functions RTRIM char value expr gt Returns a character string based on char value expr gt with the trailing space characters removed Equivalent to SQL Foundation TRIM TRAILING FROM character string gt JDBC SOUNDEX SOUNDEX char value expr gt Returns a four character code representing the sound of char value expr gt The US census algorithm is used For example the soundex value for Washington is W252 JDBC SPACE SPACE count Returns a character string consisting of count spaces JDBC SUBSTR SUBSTR SUBSTRING char value expr offset length The JDBC version of SQL Founda
141. value expression gt Specify a pattern match comparison for character or binary strings The row value predicand gt is always a lt string value expression gt of character or binary type The lt character pattern gt or lt octet pattern isa string value expression in which the underscore and percent characters have special meanings The underscore means match any one character while the percent means match a sequence of zero or more characters The lt escape character gt or lt escape octet gt isalsoa lt string value expression gt that evaluates to a string of exactly one character length If the underscore or the percent is required as normal characters in the pattern the specified escape character or escape octet gt can be used in the pattern before the underscore or the percent The row value predicand gt is compared with the character pattern and the result of comparison is returned If any of the expressions in the predicate evaluates to NULL the result of the predicate is UNKNOWN The expression A NOT LIKE Bisequivalentto NOT A LIKE B Ifthe length of the escape is not 1 or it is used in the pattern not immediately before an underscore or a percent character an exception is raised IS NULL null predicate null predicate row value predicand IS NOT NULL Specify a test for a null value The expression X IS NOT NULL is NOT equivalent to NOT X IS NULL ifthe degree of the row value predicand
142. variable number of arguments Also see the Data Access and Change chapter for SQL expressions that are similar to functions for example CAST and NULLIF CASEWHEN CASEWHEN boolean value expr gt lt value expr 2 gt lt value expr 3 If the boolean value expr gt is true returns lt value expr 2 otherwise returns lt value expr 3 Use a CASE WHEN expression instead for more extensive capabilities and options CASE WHEN is documented in the Data Access and Change chapter HyperSQL 191 HyperSGL Built In Functions COALESCE COALESCE lt value expr 1 lt value expr 2 gt Returns lt value expr 1 ifitis not null otherwise returns value expr 2 if not null and so on The type of both arguments must be comparable Foundation CONVERT CONVERT value expr gt data type data type SQL BIGINT SQL BINARY SQL BIT SQL BLOB SQL BOOLEAN SQL CHAR SQL CLOB SQL DATE SQL DECIMAL SQL DATALINK SQL DOUBLE SOL FLOAT SQL INTEGER SQL LONGVARBINARY SQL LONGNVARCHAR SQL LONGVARCHAR SQL NCHAR SQL NCLOB SQL NUMERIC SQL NVARCHAR SQL REAL SQL ROWID SOL SOLXML SOL SMALLINT SOL TIME SOL TIMESTAMP SOL TINYINT SQL_VARBINARY SQL_VARCHAR lt precision length or scale parameters gt The CONVERT function is a JDBC escape function equivalent to the SQL standard C
143. 0 000 row combinations With an index on t2 c2 this is reduced to 10 000 row checks and index lookups With the additional index on t2 c2 only about 4 rows are checked to get the first result row Note that in HSQLDB an index on multiple columns can be used internally as a non unique index on the first column in the list For example CONSTRAINT namel UNIQUE cl c2 c3 means there is the equivalent of 26 HyperSGL SQL Language CREATE INDEX name2 ON atable c1 So you do not need to specify an extra index if you require one on the first column of the list In HyperSQL 2 0 a multi column index will speed up queries that contain joins or values on the first n columns of the index You need NOT declare additional individual indexes on those columns unless you use queries that search only on a subset of the columns For example rows of a table that has a PRIMARY KEY or UNIQUE constraint on three columns or simply an ordinary index on those columns can be found efficiently when values for all three columns or the first two columns or the first column are specified in the WHERE clause For example SELECT FROM tl WHERE tl cl 4 AND tl c2 6 AND t1 c3 8 willuseanindex on t1 c1 c2 c3 if it exists A multi column index will not speed up queries on the second or third column only The first column must be specified in the JOIN ON or WHERE conditions Sometimes query speed depends on t
144. 0 have a connection property get column name which defaults to true in version 2 0 but defaulted to false in some releases of version 1 8 x You have to explicitly specify this property as false if you want non standard behaviour get ColumnName to return the same value as getColumnLabel HyperSQL Dependency Settings for Applications Dependency settings using Gradle Ivy Maven Groovy This section is about building applications that have build time dependencies upon HyperSQL and for executions that use a dependency library system Examples of the second type are unit test runs job runs triggered by a build system or systems like Grape that pull libraries from the network at end user run time What version to Pull The best option for most developers is to use our snapshot repository or at least to depend upon the latest public version of HyperSQL with a range pattern like 2 Here are exceptional cases where you should depend on a static version Your application has code dependencies upon version specific details of the HyperSQL distribution In this case the specific dependency specification should be checked in to your source code control system alongside the code that manifests the version dependency If your code is enhanced to use a newer version of HyperSQL you should update the version specification so that whenever code configs are checked out the dependency will always match the code Yourorganization only
145. 0 means no log Level 1 means only important error events Level 2 means more events including both important and less important normal events Level 3 includes even more details For readonly and mem databases if the level is set above 0 the log messages are directed to stderr The events are logged in a file with the extension app log alongside the main database files This is equivalent to the connection property hsqldb applog When the SQL option is used this statement logs the SQL statements as they are executed Each log line contains the timestamp and the session number followed by the SQL statement and JDBC arguments if any Levels 1 and 2 are supported Level 1 only logs commits and rollbacks while Level 2 logs all statements The logged lines are stored in a file with the extension sql log alongside the main database files Only a user with the DBA role can execute this statement This is equivalent to the connection property hsqldb sqllog SET DATABASE GC set database gc statement ll a set database gc statement ET DATABASE GC unsigned integer literal 212 HyperSGL System Management An optional property which forces calls to System gc after the specified number of row operations The default value for this property is 0 which means no System gc calls Usual values for this property range from 10000 depending on the system and the memory allocation This property may be useful in som
146. 08 CURTIME function 183 D DATA_TYPE_PRIVILEGES 76 DATABASE ISOLATION LEVEL function 196 DATABASE NAME function 194 DATABASE TIMEZONE function 182 DATABASE VERSION function 194 DATABASE function 194 DATE ADD function 187 DATE SUB function 187 DATEADD function 187 DATEDIFF function 187 datetime and interval literal 102 Datetime Operations 18 DATETIME types 17 datetime value expression 109 datetime value function 109 DAYNAME function 184 DAYOFMONTH function 184 DAYOFWEEK function 184 DAYOFYEAR function 184 DAYS function datetime 184 DBA ROLE 88 DECLARE CURSOR 99 DECLARE HANDLER 147 DECLARE variable 146 DECODE function 192 DEFAULT clause 55 DEGREES function 179 DELETE FROM 131 derived table 123 DETERMINISTIC characteristic 141 DIAGNOSTICS function 194 DIFFERENCE function 174 DISCONNECT 39 DOMAIN CONSTRAINTS 76 DOMAINS 76 DROP ASSERTION 73 DROP CAST 71 DROP CHARACTER SET 72 DROP COLLATION 72 DROP COLUMN 60 drop column idenitty generator 62 DROP CONSTRAINT 61 DROP DEFAULT table 61 DROP DOMAIN 64 DROP DOMAIN CONSTRAINT 64 DROP DOMAIN DEFAULT 64 DROP INDEX 71 DROP ROLE 92 DROP routine 68 DROP SCHEMA 52 DROP SEQUENCE 70 DROP TABLE 57 DROP TRANSLATION 73 DROP TRIGGER 66 171 DROP USER 90 DROP VIEW 63 DYNAMIC RESULT SETS 142 E ELEMENT TYPES 76 ENABLED ROLES 76 EXISTS predicate 114 EXP function 179 expression 106 external a
147. 183 CURRENT CATALOG function 195 CURRENT DATE function 183 CURRENT ROLE function 194 CURRENT SCHEMA function 195 CURRENT TIME function 183 CURRENT TIMESTAMP function 183 CURRENT USER function 194 CURRENT VALUE FOR 108 CURTIME function 183 D DATA TYPE PRIVILEGES 76 DATABASE ISOLATION LEVEL function 196 DATABASE NAME function 194 DATABASE TIMEZONE function 182 DATABASE VERSION function 194 DATABASE function 194 DATE ADD function 187 DATE SUB function 187 DATEADD function 187 DATEDIFF function 187 datetime and interval literal 102 Datetime Operations 18 DATETIME types 17 datetime value expression 109 datetime value function 109 DAYNAME function 184 DAYOFMONTH function 184 DAYOFWEEK function 184 DAYOFYEAR function 184 DAYS function datetime 184 DBA ROLE 88 DECLARE CURSOR 99 DECLARE HANDLER 147 DECLARE variable 146 DECODE function 192 DEFAULT clause 55 DEGREES function 179 DELETE FROM 131 derived table 123 DETERMINISTIC characteristic 141 DIAGNOSTICS function 194 DIFFERENCE function 174 DISCONNECT 39 DOMAIN CONSTRAINTS 76 DOMAINS 76 DROP ASSERTION 73 DROP CAST 71 DROP CHARACTER SET 72 DROP COLLATION 72 DROP COLUMN 60 drop column idenitty generator 62 DROP CONSTRAINT 61 DROP DEFAULT table 61 DROP DOMAIN 64 DROP DOMAIN CONSTRAINT 64 DROP DOMAIN DEFAULT 64 DROP INDEX 71 DROP ROLE 92 DROP routine 68 DROP SCHEMA 52 DROP SEQUENCE 70 D
148. 2 OOO ps executeUpdate Array Reference The most common operations on an array are element reference and assignment which are used when reading or writing an element of the array Unlike Java and many other languages arrays are extended if an element is assigned to an index beyond the current length This can result in gaps containing NULL elements Array length cannot exceed the maximum cardinality Elements of all arrays including those that are the result of function calls or other operations can be referenced for reading lt array element reference array value expression left bracket gt numeric value expression right bracket Elements of arrays that are table columns or routine variables can be referenced for writing This is done in a SET statement either inside an UPDATE statement or as a separate statement in the case of routine variables OUT and INOUT parameters target array element specification gt target array reference left bracket or trigraph simple value specification right bracket or trigraph target array reference SQL parameter reference column reference 24 HyperSGL SQL Language Note that only simple values or variables are allowed for the array index when an assignment is performed The examples below demonstrates how elements of the array are referenced in SELECT and an UPDATE statement SELECT scores ranking nam
149. 2000 driver requires mssqlserver jar and msutil jari driver com microsoft jdbc sqlserver SQLServerDriver username myuser password hiddenpwd Current 2011 JDBC Driver for Microsoft SQL Server Requires just the new sqljdbc4 jar Microsoft just loves back slashes url jdbc sqlserver hostname instanceName DatabaseName dbname driver com microsoft jdbc sqlserver SOLServerDriver Template for Microsoft SQL Server database using the JTDS Driver http jtds sourceforge net Jar file has name like jtds 1 2 5 jar urlid nlyte username myuser password hiddenpwd 257 HyperSGL HyperSQL on UNIX url jdbc jtds sqlserver myhost nlyte instance MSSQLSERVER driver net sourceforge jtds jdbc Driver Template for a Sybase database urlid sybase url jdbc sybase Tds hostname 4100 dbname username blaine password hiddenpwd This is for the jConnect driver requires jconn3 jar driver com sybase jdbc3 jdbc SybDriver Template for Embedded Derby Java DB urlid derbyl url jdbc derby path to derby directory create true username user name password any noauthbydefault driver org apache derby jdbc EmbeddedDriver The embedded Derby driver requires derby jar There a also the org apache derby jdbc ClientDriver driver with URL like jdbc derby lt server gt lt port gt databaseName which requires derbyclient jar You can use to commit since the Derby team decided why not to implement the SQL standard statement commit
150. 22 20 30 40 INTERVAL 20 HOUR DATEADD DATEADD field numeric value expr gt datetime valu xpr gt DATEDIFF DATEDIFF field datetime valu xpr 1 gt datetime valu xpr 2 field yy year mm month dd day hh hour mi minute ss second ms millisecond The DATEADD and DATEDIFF functions are alternatives to TIMESTAMPADD and TIMESTAMPDIFF with fewer available field options The field names are specified as strings rather than keywords The fields translate to YEAR MONTH DAY HOUR MINUTE SECOND and MILLISECOND DATEDIFF is evaluated as datetime value expr 2 datetime value expr 1 HyperSQL DATEDIFF datetime valu xpr 1 gt datetime valu xpr 2 This special form of DATEDIFF does not have a field parameter and return the number of days between two dates This form is evaluated as datetime value expr l datetime valu xpr 2 which is different from the main form This form is compatible with some other database engines HyperSQL DATEADD month 3 DATE 2008 11 22 DATEDIFF hour TIMESTAMP 2008 11 22 20 30 40 TIMESTAMP 2008 11 22 00 30 40 ROUND ROUND datetime valu xpr gt char value expr gt The datetime valu xpr is of DATE TIME or TIMESTAMP type The char value expr isa format string for YEAR MONTH WEEK OF YEAR DAY HOUR MINUTE or SE
151. 26 MySQL Style Eudr de nt pk ke DA SA 234 12 27 Oracle Style SyMtax EE 234 12 28 PostgreSQL Style Syntax Lssacccccdsdecusesceieden bokia te ok YES vi b aie tk kod ik pal m rone ke date kak etae vu book sassy 234 12 29 Default Table Lype 3 25 eee tuse teet etu eete Dep ee eese EE E O EAEE EEE EEE Sa 235 12 30 Transaction Control Mod scceim enie eei inore irune r epar on kote re qe Pak sib beue de Eo Vua ex PPAR DE ee Dr TOR Onus 235 12 31 Default Isolation Level for Sessions seeecoeecneeeecetecconersnstenceccnsnerseaeseonersnneetsonsoneneeea 235 12 32 Transaction Rollback in Deadlock 2 iiie disant pte ere tr Lote teen ne Eta on adve DP kwe akay 235 12 33 Time Zone and Interval Types ioi tte tnter Re vbt Pre Eee EC a pw EY E BEBE eX RR a UFU EXE En EES 235 12 34 Opening Database as Read Only 1 caecis esiste teste reo EEEE EEEE ero bep reo E RP vwe ka nire pe RE ane 236 12 35 Opening Database Without Modifying the Files sss mH HH 236 12 36 Huge database files and tables laii eerte nere re Eee kika ak LOUE kd dak eur gane ne Dra daj SERERE en 236 12 37 Temporary Result Rows in Memory ssssss Im eme HI en mene men ee eere 236 Ima A c kn EE 237 12 39 SOL LOGGING 1 ertet rebote ere aha e bx ii ab tini se roD bk lk an m kai ak ER Dei 237 12 40 Rows Cached In Memory cesi rto pe Pete suere k
152. 3 Lock Contention in QPL siie E 33 Locks in SQL Routines and Triggers l lllllllelleooeeoooetoo eten eton I eem Hem mee mene 33 IMIV CC ie PEE 33 Choosing the Transaction Model 0 cece cece cece eee cee ce eeca e eme mH HI emen eere 34 schema and Database Change 5 eo ree ve detention ank eka van PNE de a LU ER PEE syon 35 Simultaneous Access to Tables lillllileooe toutou teneoatetoatentoeteseoteseoetossoesonsoesensousonsoosouooue 35 Viewin SESSIONS MERE 35 Session and Transaction Control Statements eene mee nehmen hene nnne 35 4 schemas and Database ODJECtS cicoria rE orbe Let e po cane E dev EDU REP ye eske ese SURE QUNM NO ee 42 CAVE VIEW eta se rel ke E ol PIRE rd e wea n Eu INE Per dM kon gre a ek eu INED era Ec iate teye ke ODE iS ES 42 Schemas and Schema Objects ee tte thereon eee debi e eese eene Ja aki sa sere sedeo kab kk esse 42 Names and References eecossuotexoectt poison sd eee fetay apts dese ten geese vie dedan peta Yo pur aw 43 ricus gl M ET 43 EI ACT m 44 Distinet Types iter taxe EAER ette testae Eres pe vere eese eoe ce EVER E EX RV P kaa kak DE reve OE T 44 IBinP Mm 44 Number Seguentes sesine M ER So e De ee RON Eb ke a ee 44 jb ge kipa Anti 46 VIEWS EUROS 47 SIE c 47 ASSSOTIONS 225
153. 4 ocior epresis o so pacte si onsale te thiles Juve quaduenndsuce o E Tesi der E iE EEEn 129 OTACANP seei roren e aa tat eto ka a oux ok pan e pe a A dis e mi a pe ctetu ne dieu our sis Padus 130 Mund valer sant eki enpi en r a eke ae ii e a e ren ae a ik konin eee a ea ka eke gen v 131 Data Change Statements we deye rm 131 HyperSGL HyperSQL User Guide Delete Statement ere aa en ere nt ali end epe antes utet ee e yen ee e ta e ra on PO tut ares ren den 131 Truncate Statement aie m 132 Insert Statement soc geisere toto ati ve nin a role ea vate ep e E a segs aa Pe eke kn AS 133 Wpdate Statement 2 ecce otra e ye ie se ex eco vue ke ke po e YA An Sete ka kt onlo 134 Merge Statement se ones ee tee ene T 135 Diagnostics and State eH 136 8 JOL INVOKEU ROUTINES pratik keyi a etone ea e ea de te kk kk ke pe aie re op n ben e loa epe frs retni 138 Routine Definition M 139 Routine Characteristics vekse tans akonbofe seen envi do konpak I bese eko pies eka Tbe POETE RN 141 SQL Language Routines PSM ee eene ee hne toseousossousousousossouoonoousonnounon 143 Advantages and Disadvantages sssssesssee HH He HI eere hen rentrer 143 Routine Statements wicisssicecdeves m 144 Sereni MEER 145 Table Variables e 145 har peyi 145 ucl MM eT 146 Handlers e vet pea an ka ate dent e n e ero ke ke ep e yad kane ane tk a e
154. 5 23 00 00 DAY TO SECOND A numeric value can be cast to an interval type In this case the numeric value is first converted to a single field INTERVAL type with the same field as the least significant field of the target interval type This value is then converted to the target interval type For example CAST 22 AS INTERVAL YEAR TO MONTH evaluates to INTERVAL 22 MONTH and then INTERVAL 1 10 YEAR TO MONTH Note that SQL Standard only supports casts to single field INTERVAL types while HyperSQL allows casting to multi field types as well An interval value can be cast to a numeric type In this case the interval value is first converted to a single field INTERVAL type with the same field as the least significant filed of the interval value The value is then converted to the target type For example CAST INTERVAL 1 11 YEAR TO MONTH AS INT evaluates to INTERVAL 23 MONTH and then 23 An interval value can be cast into a character type which results in an INTERVAL literal A character value can be cast into an INTERVAL type so long as it is a string with a format compatible with an INTERVAL literal Two interval values can be added or subtracted so long as the types of both are based on the same field i e both are based on MONTH or SECOND The values are both converted to a single field interval type with same field as the 21 HyperSGL SQL Language least significant field between the two types After addition or subtra
155. 6 CASEWHEN function 191 CASE WHEN in routines 150 CAST 107 CEIL function 178 CHANGE AUTHORIZATION 88 CHAR LENGTH 173 CHARACTER LENGTH 173 CHARACTER SETS 75 character literal 100 CHARACTER types 14 character value function 109 CHAR function 173 CHECK CONSTRAINT ROUTINE USAGE 76 CHECK CONSTRAINTS 75 CHECK constraint 57 CHECKPOINT 211 COALESCE expression 106 COALESCE function 191 COLLATE 118 COLLATIONS 76 COLUMN COLUMN USAGE 76 COLUMN DOMAIN USAGE 76 COLUMN PRIVILEGES 76 COLUMN UDT USAGE 76 column definition 53 column name list 124 column reference 104 COLUMNS 76 COMMENT 51 COMMIT 38 comparison predicate 111 CONCAT function 173 CONSTRAINT 118 CONSTRAINT COLUMN USAGE 76 CONSTRAINT TABLE USAGE 76 CONSTRAINT table constraint 55 CONSTRAINT name and characteristics 55 contextually typed value specification 104 CONVERT function 192 COS function 179 COT function 179 CREATE SCHEMA ROLE 88 CREATE AGGREGATE FUNCTION 161 CREATE ASSERTION 73 CREATE CAST 71 CREATE CHARACTER SET 72 296 HyperSGL SQL Index CREATE COLLATION 72 CREATE DOMAIN 63 CREATE FUNCTION 139 CREATE INDEX 70 CREATE PROCEDURE 139 CREATE ROLE 91 CREATE SCHEMA 51 CREATE SEQUENCE 68 CREATE TABLE 52 CREATE TRANSLATION 72 CREATE TRIGGER 64 169 CREATE TYPE 71 CREATE USER 90 CREATE VIEW 62 CROSS JOIN 125 CRYPT KEY function 193 CURDATE function
156. ABASE EVENT LOG SQL LEVEL 0 1 2 Table 12 40 Rows Cached In Memory Name Description hsqldb cache_free_count maximum number of unused space recovery The default indicates 512 unused spaces are kept for later use The value can range between 0 8096 When rows are deleted the space is recovered and kept for reuse for new rows If too many rows are deleted the smaller recovered spaces are lost and the largest ones are retained for later use Normally there is no need to set this property this property cannot be set with an SQL statement Table 12 41 Rows Cached In Memory Name Default Description hsqldb cache rows maximum number of rows in memory cache Indicates the maximum number of rows of cached tables that are held in memory The value can range between 100 4 billion If the value is set via SET FILES then it becomes effective after the next database SHUTDOWN or CHECKPOINT SET FILES CACHE ROWS numeric value Table 12 42 Size of Rows Cached in Memory Name Default Description hsqldb cache size memory cache size Indicates the total size in kilobytes of rows in the memory cache used with cached tables This size is calculated as the binary size of the rows for example an INTEGER is 4 bytes The actual memory size used by the objects is 237 HyperSGL Properties Name Default Description 2 to 4 times this valu
157. ACT leaving the other part to be performed automatically at the next startup This command produces a full script of the database which can be edited for special purposes prior to the next startup Only a user with the DBA role can execute this statement BACKUP DATABASE backup database statement backup database statement BACKUP DATABASE TO file path SCRIPT NOT COMPRESSED NOT BLOCKING Backup the database to specified lt file path gt for archiving purposes The file path can be in two forms If the file path ends with a forward slash it specifies a directory In this case an automatic name for the archive is generated that includes the date time and the base name of the database The database is backed up to this archive file in the specified directory The archive is in tar gz or tar format depending on whether it is compressed or not If the file path does not end with a forward slash it specifies a user defined file name for the backup archive The file extension must be either tar gz or tar and this must match the compression option The default set of options is COMPRESSED BLOCKING If SCRIPT is specified the backup will contain a script file which contain all the data and settings of the database Otherwise it consists of the current snapshot of all database files If NOT COMPRESSED is specified the backup is a tar file without compression Otherwise it is in gzip f
158. AD_FILE LOAD_FILE lt char value expr 1 gt lt char value expr 2 gt Returns a BLOB or CLOB containing the URL or file path specified in the first argument If used with a single argument the function returns a BLOB If used with two arguments the function returns a CLOB and the second argument is the character encoding of the file HyperSQL NULLIF NULLIF lt value expr 1 gt lt value expr 2 Returns lt value expr 1 gt if it is not equal to lt value expr 2 otherwise returns null The type of both arguments must be the same This function is a shorthand for a specific CASE expression Foundation NVL NVL lt value expr 1 gt lt value expr 2 gt Returns lt value expr 1 gt if itis not null otherwise returns lt value expr 2 The type of the return value is the type of lt value expr l For example if lt value expr 1 gt isan INTEGER column and lt value expr 2 is a DOUBLE constant the return type is cast into INTEGER This function is similar to IFNULL HyperSQL NVL2 NVL2 lt value expr 1 gt lt value expr 2 gt lt value expr 3 gt If lt value expr 1 gt is not null returns lt value expr 2 gt otherwise returns lt value expr 3 gt The type of the return value is the type of lt value expr 2 gt unless it is null HyperSQL UUID UUID char value expr gt binary value expr gt With no parameter this function returns a new UUID value as a 16 byte binary value With
159. ALE 218 SET DATABASE SQL CONCAT NULLS 217 SET DATABASE SQL CONVERT TRUNCATE 217 SET DATABASE SQL DOUBLE NAN 218 SET DATABASE SQL NAMES 214 SET DATABASE SQL NULLS FIRST 218 SET DATABASE SQL REFERENCES 215 SET DATABASE SQL REGULAR NAMES 214 SET DATABASE SQL SIZE 214 SET DATABASE SQL SYNTAX DB2 219 SET DATABASE SQL SYNTAX MSS 219 SET DATABASE SQL SYNTAX MYS 219 SET DATABASE SQL SYNTAX ORA 220 SET DATABASE SQL SYNTAX PGS 220 SET DATABASE SQL TDC DELETE 215 SET DATABASE SQL TRANSLATE TTI TYPES 216 SET DATABASE SQL TYPES 215 216 SET DATABASE SQL UNIQUE NULLS 217 SET DATABASE TEXT TABLE DEFAULTS 214 SET DATABASE TRANSACTION CONTROL 213 SET DATABASE TRANSACTION ROLLBACK ON CONFLICT 213 SET DATABASE UNIQUE NAME 213 SET DATA TYPE 61 SET DEFAULT 61 SET DOMAIN DEFAULT 64 SET FILES BACKUP INCREMENT 221 SET FILES CACHE ROWS 221 299 HyperSGL SQL Index SET FILES CACHE SIZE 221 SET FILES DEFRAG 222 SET FILES LOB SCALE 224 SET FILES LOG 222 SET FILES LOG SIZE 222 SET FILES NIO 222 SET FILES NIO SIZE 223 SET FILES SCALE 223 SET FILES SCRIPT FORMAT 224 SET FILES WRITE DELAY 223 set function specification 106 SET IGNORECASE 41 SET INITIAL SCHEMA 91 SET MAXROWS 41 SET OPERATIONS 128 SET PASSWORD 91 SET PATH 40 SET REFERENTIAL INTEGRITY 220 SET ROLE 39 SET SCHEMA 40 SET SESSION AUTHORIZATION 39 SET SESSION CHARACTERISTICS 39 SET SESSION RESULT
160. AND lt row value predicand gt Lr Specify a range comparison The default is ASYMMETRIC The expression X BETWEEN Y AND Zisequivalent to X gt Y AND X lt Z Therefore if Y gt Z the BETWEEN expression is never true The expression X BETWEEN SYMMETRIC Y AND Zisequivalentto X gt Y AND X lt Z OR X gt Z AND X lt Y The expression Z NOT BETWEEN isequivalentto NOT Z BETWEEN Ifany of the three row value predicand evaluates to NULL the result is UNKNOWN IN in predicate in predicate row value predicand gt NOT IN in predicate value in predicate value table subquery left paren in value list right paren left paren UNNEST left paren array value expression right paren right paren in value list row value expression comma row value expression Specify a quantified comparison The expression X NOT IN Y isequivalentto NOT X IN Y The in value list is converted into a table with one or more rows The expression X IN Y is equivalent to X ANY Y whichisa quantified comparison predicate If the table subquery gt returns no rows the result is FALSE Otherwise the row value predicand is compared one by one with each row of the table subquery gt If the comparison is TRUE for at least one row the result is TRUE If the comparison is
161. ANT SELECT ON CD TO JOE It is not really necessary to create a schema and all its objects as one command The schema can be created first and its objects can be created one by one DROP SCHEMA drop schema statement drop schema statement DROP SCHEMA IF EXISTS schema name IF EXISTS drop behavior This command destroys an existing schema If drop behavior is RESTRICT the schema must be empty otherwise an error is raised If CASCADE is specified then all the objects contained in the schema are destroyed with a CASCADE option Table Creation CREATE TABLE table definition table definition CREATE table scope table type TABLE table name table contents source ON COMMIT PRESERVE DELETE ROWS table scope GLOBAL LOCAL TEMPORARY lt table type gt MEMORY CACHED lt table contents source gt lt table element list gt lt as subquery clause gt table element list left paren table element comma lt table element right paren table element column definition table constraint definition like clause like clause 52 HyperSGL Schemas and Database Objects A like clause copies all column definitions from another table into the newly created table Its three options indicate if the default clause identity column specification
162. AST expression It converts the lt value expr gt into the given lt data type gt and returns the value The lt data type gt options are synthetic names made by prefixing type names with SQL_ Some of the lt data type gt options represent valid SQL types but some are based on non standard type names namely SQL_LONGNVARCHAR SQL_LONGVARBINARY SQL_LONGVARCHAR SQL_TINYINT None of the synthetic names can be used in any other context than the CONVERT function The definition of CONVERT in the JDBC Standard does not allow the precision scale or length to be specified This is required by the SQL standard for BINARY BIT BLOB CHAR CLOB VARBINARY and VARCHAR types and is often needed for DECIMAL and NUMERIC Defaults are used for precision HyperSQL also allows the use of real type names without the SQL_ prefix In this usage HyperSQL allows the use of precision scale or length for the type definition when they are valid for the type definition When MS SQL Server compatibility mode is on the parameters of CONVERT are switched and only the real type names with required precision scale or length are allowed JDBC DECODE DECODE lt value expr main lt value expr match 1 gt lt value expr result 1 gt lt value expr default gt DECODE takes at least 3 arguments The lt value expr main is compared with lt value expr match 1 and if it matches lt value expr result 1 gt is returned If there ar
163. ATED BY DEFAULT AS SEQUENCE sequence name e In SELECT and other statements the NEXTVAL sequence name gt and LASTVAL functions are supported and translated into HyperSQL s NEXT VALUE FOR sequence name and IDENTITY expressions PostgreSQL uses a non standard expression SELECT A Test String to return a single row table The standard form is VALUES A Test String In PGS syntax mode this type of SELECT is supported HyperSQL supports SQL Standard ARRAY types PostgreSQL also supports this but not entirely according to the Standard SQL routines are portable but some syntax elements are different and require changes e You may need to use SET DATABASE SQL TDC DELETE UPDATE FALSE statements as PostgreSQL does not enforce the subtle rules of the Standard for foreign key cascading deletes and updates 206 HyperSGL System Management MySQL Compatibility MySQL had many incompatibilities with the Standard The latest versions have introduced much greater compatibly but some of these features have to be turned on via properties You should therefore check the current Standard compatibility settings of your MySQL database and use the available HyperSQL properties to achieve closer results If you avoid the few anti Standard features of MySQL you can port your databases to HyperSQL HyperSQL does not have the follow
164. CALTIME function 183 LOCALTIMESTAMP function 183 LOCATE function 174 LOCK TABLE 37 LOG10 function 180 LOG function 180 LOOP in routines 149 LPAD function 174 LTRIM function 175 MATCH predicate 114 MAX CARDINALITY function 190 MERGE INTO 135 MINUTE function 184 MOD function 180 MONTH function 185 MONTHNAME function 185 N name resolution 128 naming in joined table 127 naming in select list 127 NATURAL JOIN 125 NEXT VALUE FOR 107 NOW function 183 NULLIF function 193 NULL INPUT 142 numeric literal 101 NUMERIC types 11 numeric value expression 108 numeric value function 108 NVL2 function 193 NVL function 193 O OCTET_LENGTH function 175 OTHER type 16 OUTER JOIN 126 OVERLAPS predicate 115 OVERLAY function 175 P PARAMETERS 77 password complexity 205 PATH 118 PI function 180 POSITION_ARRAY function 190 POSITION function 175 POWER function 180 PRIMARY KEY constraint 56 PUBLIC ROLE 88 Q QUARTER function 185 298 HyperSQL SQL Index R RADIANS function 180 RAND function 180 RAWTOHEX function 175 REFERENTIAL_CONSTRAINTS 77 REGEXP_MATCHES function 175 REGEXP_SUBSTRING_ARRAY function 176 REGEXP_SUBSTRING function 176 RELEASE SAVEPOINT 38 RENAME 51 REPEAT UNTIL loop in routines 149 REPEAT function 176 REPLACE function 176 RESIGNAL STATEMENT 153 RETURN 152 RETURNS 139 REVERSE function 176 REVOKE 93 REVO
165. CG Static void i pProclest2 Gne joi ant pan Integer p3 throws java sql SQLException Connection conn DriverManager getConnection jdbc default connection java sql Statement stmt conn createStatement stmt execute INSERT INTO MYTABLE VALUES pl testl stmt execute INSERT INTO MYTABLE VALUES p2 test2 java sql ResultSet rs stmt executeQuery select from MYTABLE java sql ResultSetMetaData meta rs getMetaData int cols meta getColumnCount p3 0 Integer valueOf cols ts close ky stmt close alternative declaration with Connection parameter Jf public static void procilests Connection conn JAL pl int pi n Integer p3 throws java sql SQLException When the stored procedure is called by the user s program the value of the OUT parameter can be read after the call a CallableStatement is used to prepare the call the OUT parameter contains the return value CallableStatement c conn prepareCall call procl 1 2 c execute int value c getInt 1 Legacy Support The legacy HyperSQL statement CREATE ALIAS name FOR fully qualified Java method name is no longer supported directly It is supported when importing databases and translates to a special CREATE FUNCTION name statement that creates the function in the PUBLIC schema The direct use of a Java method as a function is still supported but deprec
166. CIMAL or NUMERIC value is part an expression the type of the result is DECIMAL or NUMERIC Similar to integral values when the result of an expression is assigned to a table column the value has to fit in the target column otherwise an error is returned This means a small 4 digit value of DECIMAL type can be assigned to a column of SMALLINT or INTEGER but a value with 15 digits cannot When a DECIMAL values is multiplied by a DECIMAL or integral type the resulting scale is the sum of the scales of the two terms When they are divided the result is a value with a scale number of digits to the right of the decimal point equal to the larger of the scales of the two terms The precision for both operations is calculated usually increased to allow all possible results The distinction between DOUBLE and DECIMAL is important when a division takes place For example 10 0 8 0 DECIMAL equals 1 2 but 10 0E0 8 0E0 DOUBLE equals 1 25 Without division operations DECIMAL values represent exact arithmetic REAL FLOAT and DOUBLE values are all stored in the database as java lang Double objects Special values such as NaN and Infinity are also stored and supported These values can be submitted to the database via JDBC PreparedStatement methods and are returned in ResultSet objects In order to allow division by zero of DOUBLE values in SQL statements which returns NaN or Infinity you should set the property hsqldb double nan as false
167. COND as listed in the table for 187 HyperSQL Built In Functions TO CHAR and TO DATE format elements see below The datetime value is rounded up or down after the specified field and the rest of the fields to the right are set to one for MONTH and DAY or zero for the rest of the fields For example rounding a timestamp value on the DAY field results in midnight the same date or midnight the next day if the time is at or after 12 noon If the second argument is omitted the datetime value is rounded to the nearest day HyperSQL TRUNC TRUNC datetime valu xpr gt char value expr gt Similar to the ROUND function the lt num value expr gt is of DATE TIME or TIMESTAMP type The lt char value expr gt is a format string such as YY or MM for YEAR MONTH WEEK OF YEAR DAY HOUR MINUTE or SECOND as listed in the table for TO CHAR and TO DATE format elements see below The datetime value is truncated after the specified field and the rest of the fields to the right are set to one for MONTH and DAY or zero for the rest of the fields For example applying TRUNC to a timestamp value on the DAY field results in midnight the same date Examples of ROUND and TRUNC functions are given below If the second argument is omitted the datetime value is truncated to midnight the same date HyperSQL ROUND TIMESTAMP 2008 08 01 20 30 40 YYYY 22 009 0 1 01 0010 0 00 TRUNCA GIMESLAMP 20085 08501 20 30 40
168. CONSTRAINT CONVERT CORR e CORRESPONDING COUNT COVAR POP COVAR SAMP CREATE CROSS CUBE CUME DIST CURRENT CURRENT CATALOG CURRENT DATE CURRENT DEFAULT TRANSFORM GROUP CURRENT PATH CURRENT ROLE CURRENT SCHEMA CURRENT TIME CURRENT TIMESTAMP e CURRENT TRANSFORM GROUP FOR TYPE CURRENT USER CURSOR CYCLE DATE DAY DEALLOCATE DEC DECIMAL DECLARE DEFAULT DELETE DENSE RANK DEREF DESCRIBE DETERMINISTIC DISCONNECT DISTINCT DO DOUBLE DROP DYNAMIC EACH ELEMENT ELSE ELSEIF END END EXEC ESCAPE EVERY EXCEPT EXEC EXECUTE EXISTS EXIT EXP EXTERNAL EXTRACT FALSE FETCH FILTER FIRST VALUE FLOAT FLOOR FOR FOREIGN FREE FROM FULL FUNCTION FUSION GET GLOBAL GRANT GROUP GROUPING HANDLER HAVING HOLD HOUR IDENTITY IN INDICATOR INNER INOUT INSENSITIVE INSERT INT INTEGER INTERSECT INTERSECTION INTERVAL INTO IS ITERATE JOIN LAG LANGUAGE LARGE LAST VALUE LATERAL LEAD LEADING LEAVE LEFT LIKE LIKE REGEX LN LOCAL LOCALTIME LOCALTIMESTAMP LOOP LOWER 279 HyperSGL Lists of Keywords MATCH MAX MAX CARDINALITY MEMBER MERGE METHOD MIN MINUTE MOD MODIFIES MODULE MONTH MULTISET NATIONAL NATURAL NCHAR NCLOB NEW NO NONE NORMALIZE NOT NTH VALUE NTILE NULL NULLIF NUMERIC OCCURRENCES REGEX OCTET LENGTH OF OFFSET OLD ON
169. DATE returns a value of DATE type CURRENT TIME returns a value of TIME WITH TIME ZONE type LOCALTIME returns a value of TIME type CURRENT TIMESTAMP returns a value of TIMESTAMP WITH TIME ZONE type LOCALTIMESTAMP returns a value of TIMESTAMP type If the optional time precision or timestamp precision is used then the returned value has the specified fraction of the second precision Foundation NOW NOW This function is equivalent to LOCALTIMESTAMP It can be used as a no arg function as the parens are optional HyperSQL CURDATE CURDATE This function is equivalent to CURRENT DATE JDBC CURTIME CURTIME This function is equivalent to LOCALTIME JDBC SYSDATE SYSDATE This function is equivalent to LOCALTIMESTAMP HyperSQL SYSTIMESTAMP 183 HyperSGL Built In Functions SYSTIMESTAMP This no arg function is equivalent to CURRENT TIMESTAMP and is enabled in ORA syntax mode only HyperSQL TODAY TODAY This no arg function is equivalent to CURRENT DATE HyperSQL Functions to Extract an Element of a Datetime DAYNAME DAYNAME datetime valu xpr gt This function is equivalentto EXTRACT DAY NAME FROM Returnsa string in the range of Sunday Saturday JDBC DAYOFMONTH DAYOFMONTH datetime valu xpr gt This function is equivalent to EXTRACT DAY OF MONTH FROM Returns an integer va
170. Deployment Context 2520s si antiveocsean ye sise Die R ie OS bl cares Di penk e ta castes e AR e A De 199 Readonly Databases ER 200 ACID Persistence and Reliability l ll lleleeeleeeu tee tea to atan eo etat taa ten eoe ton ooesonooeoosooeoonooesonsonsonoooooe 200 Atomicity Consistency Isolation Durability 0 esee 200 Backing Up Database Catalogs 1 rr eee re S ARE dU RR ek dre PIED tva Goats 201 Making Online Backups M ene ccestsnssvirevenssisnasgenvecuunseheesneeuyevieae ve ablise veb eee sad Eei 201 Making Offline Backups oc el ener needed AEE EEE ENEE a EERE ates abe ke ead 201 Examining Backups EUER 201 Restoring a Backup Me M ET 202 Encrypted Databases 2 5 en torto wend petere pet tn velie vg eedbs e vox Sepa s Uo Te RE E even e aie po Pe REE kila 202 Creating and Accessing an Encrypted Database sse 202 eprEnaEevdnsme Mer 202 Security CofsIderations oper eur kk poe Ne l de De Gao SERE DU SERM EE ENDE ee bct ue Te kes AS rea eeu 203 Monitoring Database Operations errori trente rettet rette pre sink SUE Eee Xv erue oe bwode sven ous EE Sete ske dane 203 External Statement Level Monitoring 2 0 0 0 eee cece seen cence I HH mere reene 203 Internal Statement Level Monitoring esses e emen rene 203 Internal Event Monitoring wi eei vien ie pole REEL ea k ON Ye diab peine DIM NE d Pon ee Adeo des 203 Log4J and IDK Jogging
171. E changes day to day Some temporal expressions are retrospectively deterministic and are allowed in check constraints For example CHECK VALUE CURRENT DATE is valid because CURRENT DATE will not move backwards in time but CHECK VALUE CURRENT DATE is not acceptable If you want to enforce the condition that a date value that is inserted into the database belongs to the future at the time of insertion or any similar constraint then use a TRIGGER with the desired condition DROP TABLE drop table statement drop table statement DROP TABLE IF EXISTS table name IF EXISTS drop behavior Destroy a table The default drop behaviour is RESTRICT and will cause the statement to fail if there is any view routine or foreign key constraint that references the table If drop behavior is CASCADI E it causes all schema 57 HyperSGL Schemas and Database Objects objects that reference the table to drop Referencing views are dropped In the case of foreign key constraints that reference the table the constraint is dropped rather than the TABLE or DOMAIN that contains it Table Manipulation Table manipulation statements change the attributes of tables or modify the objects such as columns and constraints SET TABLE CLUSTERED set table clustered property set table clustered statement SET TABLE table name CLUSTERED ON left paren column name list right paren
172. E is specified then the previous CURRENT ROLE is eliminated The effect of this lasts for the lifetime of the session The current role can be accessed with the CURRENT ROLE function SET TIME ZONE set local time zone statement set local time zone statement SET TIME ZONE set time zone value set time zone value interval value expression LOCAL Set the current default time zone displacement for the current SQL session When the session starts the time zone displacement is set to the time zone of the client This command changes the time zone displacement The effect of this lasts for the lifetime of the session If LOCAL is specified the time zone displacement reverts to the local time zone of the session Example 3 8 Setting Session Time Zone SET TIME ZONE LOCAL SET TIME ZONE INTERVAL 6 00 HOUR TO MINUTE SET CATALOG set catalog statement set catalog statement SET catalog name characteristic catalog name characteristic CATALOG value specification Set the default schema name for unqualified names used in SQL statements that are prepared or executed directly in the current sessions As there is only one catalog in the database only the name of this catalog can be used The current catalog can be accessed with the CURRENT CATALOG function SET SCHEMA set schema statement set schema statement SET schema name characteristic
173. E writeability set table write property set table read only statement SET TABLE table name READ ONLY READ WRITE Set the writeability property of a table Tables are writeable by default This statement can be used to change the property between READ ONLY and READ WRITE This is a feature of HyperSQL SET TABLE SOURCE set table source statement set table source statement gt SET TABLE table name SOURCE file and options gt DESC file and options gt doublequote file path lt semicolon gt lt property gt doublequote 58 HyperSQL Schemas and Database Objects Set the text source for a text table This statement cannot be used for tables that are not defined as TEXT TABLE Supported Properties quoted true false all_quoted true false encoding lt encoding name gt ignore first true false cache_scale lt numeric value gt cache_size_scale lt numeric nearly 800 rows value gt r to 256 bytes per row fs lt unquoted character gt field separator vs lt unquoted character gt varchar separator Special indicators for HyperSQL Text Table separators semi quote space apos n r t AAA semicolon quote space character apostrophe newline Used as an end anchor like in regular expressions carriage return tab backslash a Unicode character specified in
174. ELETE queries are performed on CACHED tables the full set of rows that are affected including those affected due to ON UPDATE actions is held in memory for the duration of the operation This means it may not be possible to perform deletes or updates involving very large numbers of rows of CACHED tables Such operations should be performed in smaller sets This memory is released as soon as the DELETE or UPDATE is performed When transactions support is enabled with SET AUTOCOMMIT FALSE lists of all insert delete or update operations are stored in memory so that they can be undone when ROLLBACK is issued For CACHED tables only the transaction information is held in memory not the actual rows that have changed Transactions that span thousands of modification to data will take up a lot of memory until the next COMMIT or ROLLBACK clears the list Each row modification uses less than 100 bytes until COMMIT When subqueries or views are used in SELECT and other statements transient tables are created and populated by the engine If the SET SESSION RESULT MEMORY ROWS lt integer gt statement has been used these transient tables are stored on disk when they are larger than the threshold Data Cache Memory Allocation With CACHED tables the data is stored on disk and only up to a maximum number of rows are held in memory at any time The default is up to 50 000 rows The SET FILES CACHE ROWS command or the hsqldb cache_rows con
175. ERT statement you will get the same value as required by the Standard The correct way to use a sequence value is the NEXT VALUE FOR expression HyperSQL adds an extension to Standard SQL to return the last value returned by the NEXT VALUE FOR expression in the current session After a statement containing NEXT VALUE FOR is executed the value that was returned for NEXT VALUE FOR is available using the CURRENT VALUE FOR expression In the example below the NEXT VALUE FOR expression is used to insert a new row The value that was returned by NEXT VALUE FOR is retrieved with the CURRENT VALUE FOR in the next insert statements to populate two new rows in a different table that has a parent child relationship with the first table For example if the value 15 was returned by the sequence the same value 15 is inserted in the three rows Example 4 3 using the last value of a sequence INSERT INTO mytable VALUES 2 John NEXT VALUE FOR mysequence INSERT INTO childtable VALUES 4 CURRENT VALUE FOR mysequence INSERT INTO childtable VALUES 5 CURRENT VALUE FOR mysequence The INFORMATION SCHEMA SEQUENCES table contains the next value that will be returned from any of the defined sequences The SEQUENCE NAME column contains the name and the NEXT VALUE column contains the next value to be returned Note that this is only for getting information and you should not use it for accessing the next sequence value When multiple sessions access the same
176. ES LOG FALSE 270 HyperSQL Deployment Guide With this setting no data is logged but all the changes to cached tables are written to the data file To persist all the data changes up to date you can use the CHECKPOINT command If you perform SHUTDOWN the data is also persisted correctly If you do not use CHECKPOINT or SHUTDOWN when you terminate the application all the changes are lost and the database reverts to its original state when it is opened without losing any of the original data Your server applications can use a database as a temporary disk data cache which is not persisted past the lifetime of the application For this usage delete the database files when the application ends On some platforms such as embedded devices which have a reliable storage device this is also a useful option Your application issues CHECKPOINT to save the changes made so far This method of use reduces write operations on SSD devices For this usage the lock file should also be disabled with the connection property hsqldb lock file false Bulk Inserts Updates and Deletes Bulk inserts deletes and updates are performed with the best performance with the following method The database remains safe and consistent using this method In the event of a machine crash during the operation the database can be recovered to the point just before the bulk operation 1 Before the operation execute the SET FILES LOG FALSE statement 2 Execute
177. ET DATABASE SQL TDC DELETE TRUE FALSE sql enforce_tdc_update enforcing triggered data change violation for updates The ON DELETE and ON UPDATE clauses of foreign key constraints cause data changes in rows in different tables or the same table With multiple constraint a field may be updated by two constraints and set to different values This is not allowed by default Changing this property to false allows such violations of the Standard to pass without an exception Used for porting from database engines that do not enforce the constraints properly SET DATABASE SQL TDC UPDATE TRUE FALSE Table 12 16 Use of LOB for LONGVAR Types Name Default Description sql longvar_is_lob translating longvarchar and longvarbinary to lob This property when set true causes type declarations using LONGVARCHAR and LONGVARBINARY to be translated to CLOB and BLOB respectively By default they are translated to VARCHAR and VARBINARY SET DATABASE SQL LONGVAR IS LOB TRUE FALSE Table 12 17 Concatenation with NULL Name Description sql concat_nulls behaviour of concatenation involving one null This property when set false causes the concatenation of a null and a not null value to return the not null value By default it returns null SET DATABASE SQL CONCAT NULLS TRUE FALSE Table 12 18 NULL in Multi Column UNIQUE Constraints Name Descript
178. FALSE for all rows the result is FALSE Otherwise the result is UNKNOWN HyperSQL supports an extension to the SQL Standard to allow an array to be used in the in predicate value This is intended to be used with prepared statements where a variable length array of values can be used as the parameter value 112 HyperSGL Data Access and Change for each call The example below shows how this is used in SQL The JDBC code must create a new java sql Array object that contains the values and set the parameter with this array SELECT FROM customer WHERE firstname IN UNNEST Connection conn PreparedStatement ps conn and ps are instantiated here Array arr conn createArrayOf INTEGER new Integer 1 2 3 pS sctArray ll arry ResultSet rs ps executeQuery LIKE like predicate lt like predicate gt lt character like predicate gt lt octet like predicate gt lt character like predicate gt lt row value predicand gt NOT LIKE lt character pattern gt ESCAPE lt escape character gt lt character pattern gt lt character value expression gt lt escape character gt lt character value expression gt lt octet like predicate gt lt row value predicand gt NOT LIKE lt octet pattern gt ESCAPE lt escape octet gt lt octet pattern gt lt binary value expression gt lt escape octet gt lt binary
179. Forcing Garbage Collection Name Default Description runtime gc interval forced garbage collection 240 HyperSGL Properties Name Default Description This setting forces garbage collection each time a set number of result set row or cache row objects are created The default 0 means no garbage collection is forced by the program SET DATABASE GC numeric value Crypt Properties Table 12 57 Crypt Property For LOBs Description crypt_lobs encryption of lobs If the property is true the contents of the lobs file is encrypted as well this property cannot be set with an SOL statement Table 12 58 Cipher Key for Encrypted Database Name Default Description crypt_key encryption The cipher key for an encrypted database this property cannot be set with an SQL statement Table 12 59 Crypt Provider Encrypted Database Description crypt_provider encryption The fully qualified class name of the cryptography provider This property is not used for the default security provider this property cannot be set with an SQL statement Table 12 60 Cipher Specification for Encrypted Database Name Description crypt_type encryption The cipher specification this property cannot be set with an SQL statement When connecting to an in process database creates a
180. GE Information on JAR usage by Java language FUNCTION and PROCEDURE objects ROUTINE PRIVILEGES Information on EXECUTE privileges granted on PROCEDURE and FUNCTION objects ROUTINE ROUTINE USAGE Information on PROCEDURE and FUNCTION objects that are referenced in FUNCTION and PROCEDURE definitions ROUTINE SEQUENCE USAGE Information on SEQUENCE objects that are referenced in FUNCTION and PROCEDURE definitions TI HyperSGL Schemas and Database Objects ROUTINE TABLE USAGE Information on TABLE and VIEW objects that are referenced in FUNCTION and PROCEDURE definitions ROUTINES Top level information on all PROCEDURE and FUNCTION objects in the database SCHEMATA Information on all the SCHEMA objects in the database SEQUENCES Information on SEQUENCE objects SQL FEATURES List of all SQL 2008 standard features including information on whether they are supported or not supported by HyperSQL SQL IMPLEMENTATION INFO Information on name capabilities and defaults of the database engine software SQL PACKAGES List of the SQL 2008 Standard packages including information on whether they are supported or not supported by HyperSQL SQL PARTS List of the SQL 2008 Standard parts including information on whether they are supported or not supported by HyperSQL SQL SIZING List of the SQL 2008 Standard maximum supported sizes for different features as supported by HyperSQL SQL SIZING PROFILES TABLES Information on all TABLE
181. Hour of day 00 11 HH12 Hour of day 00 11 HH24 Hour of day 00 23 MI Minute 00 59 SS Second 00 59 FF Fractional seconds Array Functions Array functions are specialised functions with ARRAY parameters or return values For the ARRAY AGG aggregate function see the Data Access and Change chapter CARDINALITY CARDINALITY array value expr gt Returns the element count for the given array argument Foundation MAX CARDINALITY MAX CARDINALITY array value expr gt Returns the maximum allowed element count for the given array argument Foundation POSITION ARRAY POSITION ARRAY value expression IN array value expr FROM int value expr Returns the position of the first match for the value expression in the array By default the search starts from the beginning of the array The optional lt int value expr gt specifies the start position Positions are counted from 1 Returns zero if no match is found HyperSQL SORT ARRAY SORT ARRAY array value expr gt ASC DESC NULLS FIRST LAST Returns a sorted copy of the array By default sort is performed in ascending order and NULL elements are sorted first HyperSQL TRIM ARRAY 190 HyperSQL Built In Functions TRIM ARRAY array value expr gt num value expr gt Returns a new array that contains the elements of the lt array value expr gt minus the number of elements specified by th
182. HyperSQL General Index Symbols _SYSTEM ROLE 88 A ABS function 178 ACL 250 ACOS function 178 ACTION_ID function 196 ADD COLUMN 60 add column identity generator 62 ADD CONSTRAINT 60 ADD DOMAIN CONSTRAINT 64 ADMINISTRABLE_ROLE_AUTHORIZATIONS 75 aggregate function 116 ALL and ANY predicates 113 ALTER COLUMN 61 alter column identity generator 62 alter column nullability 62 ALTER DOMAIN 63 ALTER INDEX 71 ALTER routine 67 ALTER SEQUENCE 69 ALTER SESSION 35 ALTER TABLE 60 ALTER USER SET INITIAL SCHEMA 91 ALTER USER SET LOCAL 91 ALTER USER SET PASSWORD 90 ALTER view 63 Ant 288 APPLICABLE_ROLES 75 ASCII function 173 ASIN function 178 ASSERTIONS 75 ATAN2 function 178 ATAN function 178 AUTHORIZATION IDENTIFIER 88 AUTHORIZATIONS 75 backup 201 BACKUP DATABASE 210 BETWEEN predicate 112 binary literal 101 BINARY types 15 BIT LENGTH function 173 BITAND function 178 BITANDNOT function 178 bitliteral 101 BITNOT function 179 BITOR function 179 BIT types 15 BITXOR function 179 boolean literal 102 BOOLEAN types 13 boolean value expression 110 C CARDINALITY function 190 CASCADE or RESTRICT 50 case expression 106 CASEWHEN function 191 CASE WHEN in routines 150 CAST 107 CEIL function 178 CHANGE AUTHORIZATION 88 CHAR LENGTH 173 CHARACTER LENGTH 173 CHARACTER SETS 75 character literal 100 CHARACTER types 14
183. HyperSQL which have all been fixed in the latest version Also HyperSQL 2 0 has been written to the SQL Standard and avoids the traps caused by superficial imitation of existing RDBMS HyperSQL has many property settings that relax conformance to the Standard in order to allow compatibility with other RDBMS without breaking the core integrity of the database These properties are modified with SET DATABASE SQL statements described in the SQL Conformance Settings section of this chapter 205 HyperSGL System Management The SQL Standard has existed since 1989 and has been expanded over the years in several revisions Also the X Open specification has defined a number of SQL functions which are implemented by most RDBMS Each RDBMS supports additional functions that are not covered by the standard Some RDBMS use non standard syntax for some operations Fortunately most popular RDBMS products have introduced better compatibility with the Standard in their recent versions but there are still some portability issues HyperSQL overcomes the potability issues using these strategies Anextensive set of functions cover the SQL Standard X Open and most of the useful functions that other RDBMS may support Database properties which can be specified on the URL or as SQL statements relax conformance to the Standard in order to allow non standard comparisons and assignments allowed by other RDBMS Specific SQL syntax compatibility modes al
184. HyperSQL User Guide HyperSQL Database Engine HSQLDB 2 2 Edited by Blaine Simpson and Fred Toussi HyperSQL HyperSQL User Guide HyperSQL Database Engine HSQLDB 2 2 by Blaine Simpson and Fred Toussi Revision 4864 Publication date 2012 08 06 00 12 50 0100 Copyright 2002 2011 The HSQL Development Group Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license You are not allowed to distribute or display this document on the web in an altered form HyperSQL Table of Contents lupe EE xiii Available formats for this document ssssssesssseseeeee ee eem ene eee hee eh enhn hen ener eres xiii 1 Runnmng and Using HyperSQL serros ance eet reto kaa ehe re Er E oet e teta ESL sein De bed dure ERR De M LEE l p L 1 The HSOLIDB JAN Mp H 1 Running Database Access TOOIS iii ettet ip yi Re kill Se ph pi as ea in l Bl k e mn lak 1 A Hyp rsQL Databas RM 2 In Process Access to Database Catalogs c ccscs ssessescsencseess anos ans seci iese Anko anban SEESE popo EEEE 3 Server MOdeS MI ai ae 3 HyperSQL HSQL Servet dm 4 EyperSQL HIT TP S TVOL Em 4 HypersQL HTTP Servlet serseri eneren lk pk ea ont ya ea in a n a e e a Di ta a a ine di An ep et 4 Connecting to d Database Server i iic eee de ensteyin a kit ol EEEIEE EREE EES EE KEETE E ECE repr EREET oa EKDE SS 4 Securty C
185. IAL FULL table subquery Specify a test for matching rows The default is MATCH SIMPLE without UNIQUE The result of the test is either TRUE or FALSE never UNKNOWN The interpretation of NULL values is different from other predicates and quite counter intuitive If the row value predicand is NULL or all of its fields are NULL the result is TRUE Otherwise the row value predicand is compared with each row of the table subquery gt If SIMPLE is specified if some field of row value predicate is NULL the result is TRUE Otherwise if row value predicate is equal to one or more rows of table subquery gt the result is TRUE if UNIQUE is not specified or if UNIQUE is specified and only one row matches Otherwise the result is FALSE If PARTIAL is specified if the non null values row value predicate are equal to those in one or more rows of table subquery gt the result is TRUE if UNIQUE is not specified or if UNIQUE is specified and only one row matches Otherwise the result is FALSE If FULL is specified if some field of row value predicate is NULL the result is FALSE Otherwise if row value predicate is equal to one or more rows of table subquery gt the result is TRUE if UNIQUE is not specified or if UNIQUE is specified and only one row matches Note that MATCH can also used be used in FOREIGN KEY constraint definitions The exact meaning is described inthe Schemas and Database Objects chapt
186. IEW TABLE USAGE Information on TABLE and VIEW objects that have been referenced in the query expressions of the VIEW objects HyperSQL Custom Views The following views are specific to HyperSQL Most of these views are used directly by JDBC DatabaseMetaData method calls and are indicated as such Some views contain information that is specific to HyperSQL and is not covered by the SQL Standard views SYSTEM BESTROWIDENTIFIER For DatabaseMetaData getBestRowldentifier SYSTEM CACHEINFO 79 HyperSGL Schemas and Database Objects Contains the current settings and variables of the data cache used for all CACHED tables and the data cache of each TEXT table SYSTEM COLUMN SEQUENCE USAGE Contains a row for each column that is defined as GENERATED BY DEFAULT AS SEQUENCE with the column name and sequence name SYSTEM COLUMNS For DatabaseMetaData getColumns contains a row for each column SYSTEM COMMENTS Contains the user defined comments added to tables and their columns SYSTEM CONNECTION PROPERTIES For DatabaseMetaData getClientInfoProperties SYSTEM CROSSREFERENCE Full list of all columns referenced by FOREIGN KEY constraints For DatabaseMetaData getCrossReference getExportedKeys and getImportedKeys SYSTEM INDEXINFO For DatabaseMetaData getIndexInfo SYSTEM PRIMARYKEYS For DatabaseMetaData getPrimaryKeys SYSTEM PROCEDURECOLUMNS For DatabaseMetaData getProcedureColumns SYSTEM PROCEDURES For DatabaseMetaData getFun
187. ION SCHEMA views CARDINAL NUMBER YES OR NO CHARACTER DATA SQL IDENTIFIER TIME STAMP All available collations are in the INFORMATION SCHEMA Views in INFORMATION SCHEMA HyperSQL supports a vast range of views in the INFORMATION SCHEMA These include views specified by the SQL Standard SQL Schemata part plus views that are specific to HyperSQL and are used for JDBC DatabaseMetaData queries which are based on SQL CLI part or other information that is not covered by the SQL Standard The names of views that are not part of SOL Schemata start with SYSTEM The views cover different types of information These are covered in the next sections Visibility of Information Users with the special ADMIN role can see the full information on all database objects Ordinary non admin users can see information on the objects for which they have some privileges The rows returned to a non admin user exclude objects on which the user has no privilege The extent of the information in visible rows varies with the user s privilege For example the owner of a VIEW can see the text of the view query but a user of the view cannot see this text When a user cannot see the contents of some column null is returned for that column Name Information The names of database objects are stored in hierarchical views The top level view is INFORMATION SCHEMA CATALOG NAME Below this level there is a group of views that covers authorizations and roles with
188. IP format and contains the normal HyperSQL database files Just use a utility such as 7Zip to expand the odb file In the db directory there are files such as script data etc Just rename these files into mydb script mydb data etc You can now open the mydb database directly with HyperSQL as an embedded database or as a server instance 293 HyperSQL Appendix D HyperSQL File Links HyperSQL Files referred to in this Guide HyperSQL files referred to in the text may be retrieved from the canonical HyperSQL documentation site http hsqldb org doc 2 0 or from the same location you are reading this page from Note If you are reading this document with a standalone PDF reader only the http hsqldb org doc 2 0 links will function Pairs of local http hsqldb org doc 2 0 links for referenced files Local apidocs org hsqldb jdbc JDBCConnection html http hsqldb org doc 2 0 apidocs org hsqldb jdbc JDBCConnection html Local apidocs org hsqldb jdbc JDBCDriver html http hsqldb org doc 2 0 apidocs org hsqldb jdbc JDBCDriver html Local apidocs org hsqldb jdbc JDBCDatabaseMetaData html http hsqldb org doc 2 0 apidocs org hsqldb jdbc JDBCDatabaseMetaData html Local apidocs org hsqldb jdbc JDBCResultSet html http hsqldb org doc 2 0 apidocs org hsqldb jdbc JDBCResultSet html Local apidocs org hsqldb jdbc JDBCStatement html http hsqldb org doc 2 0 apidocs org hsqldb jdbc JDBCStatement
189. IT handler terminates execution without undoing the data changes performed by the previous successful statements The conditions can be general conditions or specific conditions Among general conditions that can be specified SQLEXCEPTION covers all exceptions SOLWARNING covers all warnings while NOT FOUND covers the not found condition which is raised when a DELETE UPDATE INSERT or MERGE statement completes without actually affecting any row Alternatively one or more specific conditions can be specified separated with commas which apply to specific exceptions or warnings or classes or exceptions or warnings A specific condition is specified with SOLSTATE lt value gt for example SQLSTATE W_01003 specifies the warning raised after a SOL statement is executed which contains an aggregate function which encounters a null value during execution An example is given below which activates the handler when either of the two warnings is raised DECLARE UNDO HANDLER FOR SQLSTATE W 01003 W 01004 LEAVE label one The BNF for handler declaration is given below DECLARE HANDLER declare handler statement handler declaration DECLARE UNDO CONTINUE EXIT HANDLER FOR SQLEXCEPTION SOLWARNING NOT FOUND SOLSTATE state value gt lt SQL procedure statement gt A handler declaration may specify an SQL procedure statement to be performed when the handler is act
190. KE ROLE 93 RIGHT function 176 ROLE_AUTHORIZATION_DESCRIPTORS 77 ROLE_COLUMN_GRANTS 77 ROLE_ROUTINE_GRANTS 77 ROLE TABLE GRANTS 77 ROLE UDT GRANTS 77 ROLE USAGE GRANTS 77 ROLLBACK 38 ROLLBACK TO SAVEPOINT 38 ROUND function datetime 187 ROUND number function 180 ROUTINE_COLUMN_USAGE 77 ROUTINE_JAR_USAGE 77 ROUTINE_PRIVILEGES 77 ROUTINE_ROUTINE_USAGE 77 ROUTINE_SEQUENCE_USAGE 77 ROUTINE_TABLE USAGE 78 routine body 140 routine invocation 118 ROUTINES 78 ROW_NUMBER function 197 ROWNUM function 197 row value expression 105 RPAD function 176 RTRIM function 176 S SAVEPOINT 38 SAVEPOINT LEVEL 142 schema routine 66 SCHEMATA 78 SCRIPT 211 search condition 117 SECOND function 185 SECONDS SINCE MIDNIGHT function 185 SELECT 120 SELECT SINGLE ROW 148 SEQUENCE ARRAY function 191 SEQUENCES 78 SESSION ID function 196 SESSION ISOLATION LEVEL function 196 SESSION TIMEZONE function 182 SESSION USER function 195 SET AUTOCOMMIT 36 SET CATALOG 40 set clause in UPDATE and MERGE statements 134 SET CONSTRAINTS 37 SET DATABASE AUTHENTICATION FUNCTION 225 SET DATABASE COLLATION 211 SET DATABASE DEFAULT INITIAL SCHEMA 91 SET DATABASE DEFAULT ISOLATION LEVEL 213 SET DATABASE DEFAULT RESULT MEMORY ROWS 211 SET DATABASE DEFAULT TABLE TYPE 212 SET DATABASE EVENT LOG LEVEL 212 SET DATABASE GC 212 SET DATABASE PASSWORD CHECK FUNCTION 224 SET DATABASE SQL AVG SC
191. L Schemas and Database Objects The MATCH match type clause is optional and has an effect only on multi column foreign keys and only on rows containing at least a NULL in one of the lt referencing columns If the clause is not specified MATCH SIMPLE is the default If MATCH SIMPLE is specified then any NULL means the row can exist without a corresponding row in the referenced table If MATCH FULL is specified then either all the column values must be NULL or none of them MATCH PARTIAL allows any NULL but the non NULL values must match those of a row in the referenced table HyperSQL does not support MATCH PARTIAL Referential actions are specified with ON UPDATE and ON DELETE clauses These actions take place when a row in the referenced table the parent table has referencing rows in the referencing table and it is deleted or modified with any SQL statement The default is NO ACTION This means the SQL statement that causes the DELETE or UPDATE is terminated with an exception The RESTRICT option is similar and works exactly the same without deferrable constraints which are not allowed by HyperSQL The other three options CASCADE SET NULL and SET DEFAULT all allow the DELETE or UPDATE statement to complete With DELETE statements the CASCADE option results in the referencing rows to be deleted With UPDATE statements the change s to the values of the referenced columns are copied to the referencing rows With both DELETE o
192. L supports some SQL statements expressions functions and Java methods that report on the most recently executed statement The IDENTITY function returns the last inserted identity value for the current session The GET DIAGNOSTICS statement is supported to a limited extent The built in function DIAGNOSTICS is an alternative These are normally used in SQL PSM routines to check the result of the last data update operation GET DIAGNOSTICS get diagnostics statement lt get diagnostics statement gt GET DIAGNOSTICS lt simple target value specification gt ROW_COUNT 136 HyperSGL Data Access and Change The simple target value specification isa session variable or a routine variable or OUT parameter The keyword ROW COUNT specifies the row count returned by the last executed statement For INSERT UPDATE DELETE and MERGE statements this is the number of rows affected by the statement This is the same value as returned by JDBC execute methods For all other statements zero is returned The value of ROW COUNT is stored in the specified target In future versions more options will be supported for diagnostics values 137 HyperSQL Chapter 8 SQL Invoked Routines Fred Toussi The HSQL Development Group Revision 4987 Copyright 2010 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permiss
193. LASTVAL syntax and also allow compatibility with some other aspects of this dialect 234 HyperSGL Properties Name Default Description SET DATABASE SQL SYNTAX PGS TRUE FALSE Database Operations Properties Table 12 29 Default Table Type Name Description hsqldb default table type type of table created with unqualified CREATE TABLE The CREATE TABLE command results in a MEMORY table by default Setting the value cached for this property will result in a cached table by default The qualified forms such as CREATE MEMORY TABLE or CREATE CACHED TABLE are not affected at all by this property SET DATABASE DEFAULT TABLE TYPE CACHED MEMORY Table 12 30 Transaction Control Mode Name Default Description hsqldb tx database transaction control mode Indicates the transaction control mode for the database The values locks mvlocks and mvcc are allowed SET DATABASE TRANSACTION CONTROL LOCKS MVLOCKS MVCC Table 12 31 Default Isolation Level for Sessions Name hsqldb tx_level Description tat tbasa default transaction isolation level Indicates the default transaction isolation level for each new session The values read_committed and serializable are allowed Individual sessions can change their isolation level SET DATABASE DEFAULT ISOLATION LEVEL READ COMMITTED SERIALIZABLE Table 12 32 Tran
194. LE USAGE GRANTS 77 ROLLBACK 38 ROLLBACK TO SAVEPOINT 38 ROUND function datetime 187 ROUND number function 180 ROUTINE_COLUMN_USAGE 77 ROUTINE_JAR_USAGE 77 ROUTINE_PRIVILEGES 77 ROUTINE_ROUTINE_USAGE 77 ROUTINE_SEQUENCE_USAGE 77 ROUTINE_TABLE USAGE 78 routine body 140 routine invocation 118 ROUTINES 78 ROW_NUMBER function 197 ROWNUM function 197 row value expression 105 RPAD function 176 RTRIM function 176 S SAVEPOINT 38 SAVEPOINT LEVEL 142 schema routine 66 SCHEMATA 78 SCRIPT 211 search condition 117 SECOND function 185 SECONDS SINCE MIDNIGHT function 185 security 5 247 250 SELECT 120 SELECT SINGLE ROW 148 SEQUENCE ARRAY function 191 SEQUENCES 78 SESSION ID function 196 SESSION ISOLATION LEVEL function 196 SESSION TIMEZONE function 182 SESSION USER function 195 SET AUTOCOMMIT 36 SET CATALOG 40 set clause in UPDATE and MERGE statements 134 SET CONSTRAINTS 37 SET DATABASE AUTHENTICATION FUNCTION 225 SET DATABASE COLLATION 211 SET DATABASE DEFAULT INITIAL SCHEMA 91 SET DATABASE DEFAULT ISOLATION LEVEL 213 SET DATABASE DEFAULT RESULT MEMORY ROWS 211 SET DATABASE DEFAULT TABLE TYPE 212 SET DATABASE EVENT LOG LEVEL 212 SET DATABASE GC 212 SET DATABASE PASSWORD CHECK FUNCTION 224 SET DATABASE SQL AVG SCALE 218 SET DATABASE SQL CONCAT NULLS 217 SET DATABASE SQL CONVERT TRUNCATE 217 SET DATABASE SQL DOUBLE NAN 218 SET DATABASE SQL NA
195. M customer GROUP BY lastname Laura Steel John Steel John Steel Robert Steel Robert King Robert King James King George King Julia King George King Robert Sommer Janet Sommer Michael Smith Anne Smith Andrew Smith Bill Fuller Anne Fuller Laura White Sylvia White Susanne Clancy Michael Clancy Sylvia Clancy Bob Clancy Susanne Clancy John Clancy Java Aggregate Functions A Java aggregate function is defined similarly to PSM functions apart from the routine body which is defined as EXTERNAL NAME The Java function signature must follow the rules for both nullable and INOUT parameters therefore No argument is defined as a primitive or primitive array type This allows nulls to be passed to the function The second and third arguments must be defined as arrays of the JDBC non primitive types listed in the table in the previous section In the example below a user defined aggregate function for geometric mean is defined CREATE AGGREGATE FUNCTION geometric mean IN val DOUBLE IN flag BOOLEAN INOUT register DOUBLE INOUT counter INT RETURNS DOUBLE NO SQL LANGUAGE JAVA EXTERNAL NAME CLASSPATH org hsqldb test TestOl geometricMean 163 HyperSQL SQL Invoked Routines The Java function definition is given below public static Double geometricMean Double in Boolean flag Double register Integer counter if flag if register 0 null return null double a
196. MES 214 SET DATABASE SQL NULLS FIRST 218 SET DATABASE SQL REFERENCES 215 SET DATABASE SQL REGULAR NAMES 214 SET DATABASE SQL SIZE 214 SET DATABASE SQL SYNTAX DB2 219 SET DATABASE SQL SYNTAX MSS 219 SET DATABASE SQL SYNTAX MYS 219 SET DATABASE SQL SYNTAX ORA 220 SET DATABASE SQL SYNTAX PGS 220 SET DATABASE SQL TDC DELETE 215 SET DATABASE SQL TRANSLATE TTI TYPES 216 SET DATABASE SQL TYPES 215 216 SET DATABASE SQL UNIQUE NULLS 217 SET DATABASE TEXT TABLE DEFAULTS 214 SET DATABASE TRANSACTION CONTROL 213 SET DATABASE TRANSACTION ROLLBACK ON CONFLICT 213 305 HyperSQL General Index SET DATABASE UNIQUE NAME 213 SET DATA TYPE 61 SET DEFAULT 61 SET DOMAIN DEFAULT 64 SET FILES BACKUP INCREMENT 221 SET FILES CACHE ROWS 221 SET FILES CACHE SIZE 221 SET FILES DEFRAG 222 SET FILES LOB SCALE 224 SET FILES LOG 222 SET FILES LOG SIZE 222 SET FILES NIO 222 SET FILES NIO SIZE 223 SET FILES SCALE 223 SET FILES SCRIPT FORMAT 224 SET FILES WRITE DELAY 223 set function specification 106 SET IGNORECASE 41 SET INITIAL SCHEMA 91 SET MAXROWS 41 SET OPERATIONS 128 SET PASSWORD 91 SET PATH 40 SET REFERENTIAL INTEGRITY 220 SET ROLE 39 SET SCHEMA 40 SET SESSION AUTHORIZATION 39 SET SESSION CHARACTERISTICS 39 SET SESSION RESULT MEMORY ROWS 41 SET TABLE CLUSTERED 58 SET TABLE read write property 58 SET TABLE SOURCE 58 SET TABLE SOURCE HEADER 59 SET TABLE
197. MESTAMP value For example you cannot use the WW W HH or HH12 format elements with TO DATE or TO TIMESTAMP The format is internally translated to a java text SimpleDateFormat format string Unsupported format strings should not be used With TO_CHAR you can include a string literal inside the format string by enclosing it in double quotes HyperSQL The supported format components are all uppercase as follows Table 10 1 TO CHAR TO DATE and TO TIMESTAMP format elements BC B C AD A D Returns AD for common era and BC for before common era RRRR 4 digit year YYYY 4 digit year IYYY 4 digit year corresponding to ISO week of the year The reported year for the last few days of the calendar year may be the next year YY 2 digit year IY 2 digit year corresponding to ISO week of the year MM Month 01 12 MON Short three letter name of month MONTH Name of month 189 HyperSGL Built In Functions WW Week of year 1 53 where week 1 starts on the first day of the year and continues to the seventh day of the year not a calendar week W Week of month 1 5 where week 1 starts on the first day of the month and ends on the seventh not a calendar week IW Week of year 1 52 or 1 53 based on the ISO standard Week starts on Monday The first week may start near the end of previous year DAY Name of day DD Day of month 01 31 DDD Day of year 1 366 DY Short three letter name of day HH
198. NDEX can be added to the end of the query to force the use of the index for the LIMIT operation In the example below there is an index on TA COLI as well as the index on TA COL3 Normally the index on TA COLI is used but the USING INDEX hint results in the index on TB COL3 to be used for selecting the first 1000 rows TA is a very large table with an index on TA COL3 and a separate index on TA COL1 SELECT FROM TA JOIN TB ON TA COL2 TB COL1 WHERE TA COL1 SENT AND TB COL3 gt 40000 ORDER BY TB COL3 LIMIT 1000 USING INDEX 29 HyperSQL Chapter 3 Sessions and Transactions Fred Toussi The HSQL Development Group Revision 4903 Copyright 2010 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Overview All SQL statements are executed in sessions When a connection is established to the database a session is started The authorization of the session is the name of the user that started the session A session has several properties These properties are set by default at the start according to database settings SQL Statements are generally transactional statements When a transactional statement is executed it starts a transaction if no transaction is
199. NT EGENT KEN M MENTI ESIEN SELECT d e f FROM atable WHERE a b c GROUP BY d e f SELECT d e SUM f FROM atable WHERE a b c GROUP BY d e HAVING SUM f gt 2 AND d e 4 A having clause filters the rows of the table that is formed after applying the group by clause using its search condition The search condition must be an expression based on the expressions in the GROUP BY list or the aggregate functions used Table Primary Table primary refers to different forms of table reference in the FROM clause The simplest form of reference is simply a name This is the name of a table a view a transition table in a trigger definition or a query name specified in the WITH clause of a query expression 122 HyperSGL Data Access and Change table or query name table name transition table name query name derived table A query expression that is enclosed in parentheses and returns from zero to many rows isa table subquery gt In a derived table the query expression is self contained and cannot reference the columns of other table references This is the traditional and most common form of use ofa table subquery derived table table subquery gt LATERAL When the word LATERAL is used before a table subquery it means the query expression can reference the columns of other table references that go before it lateral derived table LATERAL table subq
200. New Database Name Default Description ifexists connect only if database already exists Has an effect only with mem and file database When true will not create a new database if one does not already exist for the URL When the property is false the default a new mem or file database will be created if it does not exist Setting the property to true is useful when troubleshooting as no database is created if the URL is malformed Example below jdbc hsqldb file enrolments ifexists true create create the database if it does not exist Similar to the ifexists property but with opposite meaning Has an effect only with mem and file database When false will not create a new database if one does not already exist for the URL When the property is true the default a new mem or file database will be created if it does not exist Setting the property to true is useful when troubleshooting as no database is created if the URL is malformed Example below jdbc hsqldb file enrolments create false 229 HyperSGL Properties Table 12 8 Automatic Shutdown Name Default Description shutdown shut down the database when the last connection is closed If this property is true when the last connection to a database is closed the database is automatically shut down The property takes effect only when the first connection is made to the database This means the connection
201. OFF Subsequently mytable will be empty and read only However the data source description will be preserved and the table can be re connected to it with SET TABLE mytable SOURCE ON When a database is opened if the source file for an existing text table is missing the table remains disconnected from its data source but the source description is preserved This allows the missing source file to be added to the directory and the table re connected to it with the above command Disconnecting text tables from their source has several uses While disconnected the text source can be edited outside HSQLDB provided data integrity is respected When large text sources are used and several constraints or indexes 84 HyperSGL Text Tables need to be created on the table it is possible to disconnect the source during the creation of constraints and indexes and reduce the time it takes to perform the operation Text File Usage The following information applies to the usage of text tables Text File Issues File locations are restricted to below the directory that contains the database unless the textdb allow full path property is set true as a Java system property This feature is for security otherwise an admin database user may be able to open random files The specified text source path is interpreted differently according to this property By default the path is interpreted as a relative path to the direc
202. ON LEVEL Returns the default transaction isolation level for the current session Returns either READ COMMITTED or SERIALIZABLE as a string HyperSQL DATABASE ISOLATION LEVEL DATABASE ISOLATION LEVEL Returns the default transaction isolation level for the database Returns either READ COMMITTED or SERIALIZABLE as a string HyperSQL TRANSACTION SIZE TRANSACTION SIZE Returns the row change count for the current transaction Each row change represents a row INSERT or arow DELETE operation There will be a pair of row change operations for each row that is updated TRANSACTION ID TRANSACTION ID Returns the current transaction ID for the session as a BIGINT value The database maintains a global incremental id which is allocated to new transactions and new actions statement executions in different sessions This value is unique to the current transaction HyperSQL ACTION ID ACTION ID Returns the current action ID for the session as a BIGINT value The database maintains a global incremental id which is allocated to new transactions and new actions statement executions in different sessions This value is unique to the current action HyperSQL TRANSACTION CONTROL TRANSACTION CONTROL Returns the current transaction model for the database Returns LOCKS MVLOCKS or MVCC as a string HyperSQL LOB ID LOB ID column reference 196 HyperSGL Built In Functions R
203. ONSIAELATIONS EP 5 Using Multiple Databases 322 tenerte Detto tone cd pate mo rt tre Dente ek EE EEEE EE KES A e 5 Accessine the Data EE 5 Closing th Database eL 6 Creating a New Database sos csvisarsacecias betae cotes it EE e E EE aE EEEE ap ap E anb 7 2 SQL Language eee sak wel asie kow poo ve KEETE kt l EEO EEN EEEE DW ak l tj EEEE E Er ST tk ee enb rat a ke a ka a 8 Standards SUPNO ii iii ly in oi lo ol te A a Ba a n D e NE DI e 8 SOL Data and TABISS SR RO 9 Temporary Lables akite eks eistimbadilaf si baka k l te kal pi kn l Dil n e m ao a AA DA ke 9 Persistent Lables E 9 LOD Data e kitan E e ke Wap ka ee Ak n ko ep AD E assis kone tenn ao essai 10 Short Guide t Data TY C d 10 Data Types and Operations E 11 NUMeriG Types vest anle kw len inen ken de kai e de kise y ile ak ki m E ko A an ake aw KAN OKAY 11 BOOL AD PYPe M 13 Character Sting Types D iv kanson okt se be 14 Binary String Types MEET 15 Bit Stomp Ly M 15 Storage and Handling of Java Objects ssssesseeee m mene mee enne hem nennen 16 Type Length Precision and Scale aoreet uie ido thes ee p uR E re rk bob meli kinn rep EE TIER DOE 16 IDatetime ANPES bn kwit ka tek atrap estes ka as t ans Sa bone festos lwa ie a a By ose fret a RA ae A aka Bi
204. P CONCAT The CUSTOMER table that is included for tests in the DatabaseManager GUI app is the source of the data SELECT LASTNAME ARRAY AGG FIRSTNAME ORDER BY FIRSTNAME FROM Customer GROUP BY LASTNAME LASTNAME C2 Steel ARRAY John John Laura Robert King ARRAY George George James Julia Robert Robert Sommer ARRAY Janet Robert SELECT LASTNAME GROUP_CONCAT DISTINCT FIRSTNAME ORDER BY FIRSTNAME DESC SEPARATOR FROM Customer GROUP BY LASTNAME LASTNAME C2 Steel Robert Laura John hang Robert Julia James George Sommer Robert Janet Other Syntax Elements 117 HyperSGL Data Access and Change search condition search condition search condition boolean value expression Specify a condition that is TRUE FALSE or UNKNOWN A search condition is often a predicate PATH path specification path specification PATH schema name list schema name list schema name comma schema name Jj Specify an order for searching for a user defined SQL invoked routine This is not currently supported by HyperSQL routine invocation routine invocation routine invocation routine name SQL argument list routine name schema name period qualified identifier SQL argument list left paren SQL argument comma SQL argument right paren SQL
205. Phase Locking with Snapshot Isolation This model is referred to as MVLOCKS It works the same way as normal 2PL as far as updates are concerned SNAPSHOT ISOLATION is a multiversion concurrency strategy which uses the snapshot of the whole database at the time of the start of the transaction In this model read only transactions use SNAPSHOT ISOLATION While other sessions are busy changing the database the read only session sees a consistent view of the database and can access all the tables even when they are locked by other sessions for updates There are many applications for this mode of operation In heavily updated data sets this mode allows uninterrupted read access to the data Lock Contention in 2PL When multiple connections are used to access the database the transaction manager controls their activities When each transaction performs only reads or writes on a single table there is no contention Each transaction waits until it can obtain a lock then performs the operation and commits All contentions occur when transactions perform reads and writes on more than one table or perform a read followed by a write on the same table For example when sessions are working at the SERIALIZABLE level when multiple sessions first read from a table in order to check if a row exists then insert a row into the same table when it doesn t exist there will be regular contention Transaction A reads from the table then does Transaction B Now
206. Potete 17 Interval TYPES T 20 hun Mee ie kines e a kn n n e laa e l e a l anny ons eaten A OS ni e e e RA te GS 23 Afray Definition 4 win sitt aw toti sak kwa m 23 Array Referente senusien tete en piba E tal ad ne el l a e fa n ay tate ak e e A nn kap ek 24 Array OCT cc 25 Indexes and Query Speed 1 en irte br sre Site e An YE pl pate kk te au ANE a yere Ue RE e ERE hn RM DE MEN RAP ok 26 Query Processing dnd OptrmisatOD ciiesccesee eese see awa kasik sib eap pesos pe eno ske ka w kai ka kk ae po pe Eka ine at eds 27 Indexes and Conditions Xm 27 Indexes and Operations D 28 Indexes and ORDER BY OFFSET and LIMIT HH HH 28 MEI alo And M TANSACHODE rH teese enuan ETER CEEA EEE e 30 OVOETVISW M E yi ol ka oo ion kol tk sa mol e kl aa l n e a n Kl a l ta a ka Bb pro RA Alon ya bk 30 Session Attributes and Variables aie aues triples k ale bk a m Re a Doa e m W Di a tal ener ki retra 30 Session invoice mani onp vase ek a e Re t 31 SESSION Each C 31 MEI MP 31 Transactions and Concurrency Control 20 2 0 cece cece cece meme enm enhn He men men nen rere 32 TWO Phase LOCK ie T 32 iii HyperSQL HyperSQL User Guide Two Phase Locking with Snapshot Isolation 20 0 0 cece cece ee eee e cence HH 3
207. QL ALTER TABLE mytable ALTER COLUMN id DROP GENERATED SET NOT NULL alter column nullability alter column nullability SET NOT NULL Adds or removes a NOT NULL constraint from a column This option is specific to HyperSQL View Creation and Manipulation CREATE VIEW view definition view definition CREATE VIEW table name view specification AS query expression WITH CASCADED LOCAL CHECK OPTION view specification left paren view column list right paren 62 HyperSGL Schemas and Database Objects view column list column name list Define a view The query expression is a SELECT or similar statement The view column list is the list of unique names for the columns of the view The number of columns in the view column list must match the number of columns returned by the query expression If view column list is not specified then the columns of the query expression should have unique names and are used as the names of the view column Some views are updatable As covered elsewhere an updatable view is based on a single table or updatable view For updatable views the optional CHECK OPTION clause can be specified If this option is specified then if a row of the view is updated or a new row is inserted into the view then it should contain such values that the row would be includ
208. QLDB_OWNER Copy the sample file sample server proper ties to the HSQLDB OWNER S home directory and rename it to server properties As a final reminder sampleserver properties is a relative path so it is understood to be relative to your HSQLDB HOME Hsqldb Server cfg file See the HyperSQL Network Listeners chapter of the HyperSQL User Guide Each server database X setting defines a database catalog f I e an independent set of data Each server database X setting corresponds exactly to the jdbc hsqldb JDBC URL you would use if you wanted to get a direct In Process Connection to the catalog instead of serving it server database 0 file db0 db0 I suggest that for every file catalog you define you add the connection property ifexists true after the database instance is created which happens simply by starting the Server one time Just append ifexists true to the file URL like so server database 0 file db0 db0 ifexists true server dbname O defaults to i e server dbname n for n 0 but the catalog definition n will be entirely ignored for n gt 0 if you do not set server dbname n I e dbname setting is required for n gt 0 though it may be set to blank e g server dbname 3 Since the value of the first database server database 0 begins with file the catalog will be persisted to a set of files in the specified directory with names beginning with
209. ROM target table AS correlation name WHERE search condition Delete rows of a table The search condition isa boolean value expression thatis evaluated for each row of the table If the condition is true the row is deleted If the condition is not specified all the rows of the table are deleted In fact an implicit SELECT is performed in the form of SELECT FROM target table WHERE search condition and the selected rows are deleted When used in JDBC the number of rows returned by the implicit SELECT is returned as the update count If there are FOREIGN KEY constraints on other tables that reference the subject table and the FOREIGN KEY constraints have referential actions then rows from those other tables that reference the deleted rows are either deleted or updated according to the specified referential actions In the second example below the rows that have the maximum value for column A are deleted DELETE FROM T WHERE C 5 DELETE FROM T AS TT WHERE TT A SELECT MAX A FROM T Truncate Statement TRUNCATE TABLE truncate table statement truncate table statement TRUNCATE TABLE target table identity column restart option truncate options identity column restart option CONTINUE IDENTITY RESTART IDENTITY truncate options AND COMMIT NO CHECK Delete all rows of a table wi
210. ROP TABLE 57 DROP TRANSLATION 73 DROP TRIGGER 66 171 DROP USER 90 DROP VIEW 63 DYNAMIC RESULT SETS 142 E ELEMENT TYPES 76 ENABLED ROLES 76 EXISTS predicate 114 EXP function 179 expression 106 external authentication 205 EXTERNAL NAME 140 EXTRACT function 185 F FLOOR function 179 FOREIGN KEY constraint 56 FOR loop in routines 150 G generated column specification 54 GET DIAGNOSTICS 136 GRANTED BY 92 GRANT privilege 92 297 HyperSQL SQL Index GRANT role 93 GREATEST function 192 GROUPING OPERATIONS 128 H HEXTORAW function 174 HOUR function 184 identifier chain 103 identifier definition 49 IDENTITY function 194 IF EXISTS 50 IFNULL function 192 IF STATEMENT 151 INFORMATION SCHEMA CATALOG NAME 76 IN predicate 112 INSERT function 174 INSERTINTO 133 interval absolute value function 110 interval term 110 INTERVAL types 20 IS AUTOCOMMIT function 195 IS READONLY DATABASE FILES function 195 IS READONLY DATABASE function 195 IS READONLY SESSION function 195 IS DISTINCT predicate 115 ISNULL function 192 IS NULL predicate 113 ISOLATION LEVEL function 195 J JOIN USING 125 JOIN with condition 125 K KEY COLUMN USAGE 77 L LANGUAGE 141 LATERAL 123 LCASE function 174 LEAST function 193 LEFT function 174 LENGTH function 174 LIKE predicate 113 LN function 180 LOAD_FILE function 193 LOB_ID function 196 LO
211. RT routine returns a value it should be within the size and precision limits defined in the return type of the SQL invoked routine otherwise an exception is raised The scale difference are ignored and corrected For example in the above example the RETURNS CHAR VARYING 100 clause limits the length of the strings returned from the Java method to 100 But if the number of digits after the decimal point scale of a returned BigDecimal value is larger than the scale specified in the RETURNS clause the decimal fraction is silently truncated and no exception of warning is raised When the function is specified as RETURNS TABLE the static Java method should return a JOBCResultSet instance For an example of how to construct a JDBCResultSet for this purpose see the source code for the org hsqldb jdbc JDBCArray class Polymorphism If two versions of the same SQL invoked routine with different parameter types are required they can be defined to point to the same method name or different method names or even methods in different classes In the example below the first two definitions refer to the same method name in the same class In the Java class the two static methods are defined with corresponding method signatures In the third example the Java function returns a result set and the SQL declaration includes RETURNS TABLE CREATE FUNCTION an_hour_before_or_now t TIME RETURNS TIME NO SQL LANGUAGE JAVA PARAMETER STYLE JAVA E
212. SE TRUE FALSE Sets the type used for new VARCHAR table columns By default character columns in new databases are case sensitive If SET IGNORECASE TRUE is used all VARCHAR columns in new tables are set to VARCHAR_IGNORECASE It is possible to specify the VARCHAR_IGNORECASE type for the definition of individual columns So it is possible to have some columns case sensitive and some not even in the same table This statement must be switched before creating tables Existing tables and their data are not affected 41 HyperSQL Chapter 4 Schemas and Database Objects Fred Toussi The HSQL Development Group Revision 5039 Copyright 2009 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Overview The persistent elements of an SQL environment are database objects The database consists of catalogs plus authorizations A catalog contains schemas while schemas contain the objects that contain data or govern the data Each catalog contains a special schema called INFORMATION_SCHEMA This schema is read only and contains some views and other schema objects The views contain lists of all the database objects that exist within the catalog
213. SE SQL NULLS FIRST TRUE FALSE When the property is TRUE nulls appear before values in result sets with ORDER BY When set FALSE nulls appear after the values Some databases including PostgreSQL Oracle and MS SQL Server return nulls after the values The property is TRUE by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sq1 nulls first 218 HyperSGL System Management SET DATABASE SQL SYNTAX DB2 set database sql syntax DB2 lt set database sql syntax DB2 statement gt SET DATABASE SQL SYNTAX DB2 TRUE FALSE This property when set TRUE enables support for some elements of DB2 syntax Single row SELECT statements SELECT expression list without the FROM clause are supported and treated as the SQL Standard equivalent VALUES expression list The DUAL table is supported as well as the ROWNUM pseudo column BINARY type definitions such as VARCHAR L FOR BIT DATA are supported Empty DEFAULT clauses in column definitions are supported The property is FALSE by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sql syntax_db2 SET DATABASE SQL SYNTAX MSS set database sql syntax MSS lt set database sql syntax MSS statement gt SET DATABASE SQL SYNTAX MSS TRUE FALSE This property when set TRUE enables support for s
214. STRAINT definitions used for DOMAIN objects ELEMENT TYPES Information on the type of elements of ARRAY used in database columns or routine parameters and return values ENABLED ROLES Information on ROLE privileges enabled for the current session INFORMATION SCHEMA CATALOG NAME 76 HyperSGL Schemas and Database Objects Information on the single CATALOG object of the database KEY COLUMN USAGE Information on COLUMN objects of tables that are used by PRIMARY KEY UNIQUE and FOREIGN KEY constraints PARAMETERS Information on parameters of each FUNCTION or PROCEDURE REFERENTIAL CONSTRAINTS Additional information on FOREIGN KEY constraints including triggered action and name of UNIQUE constraint they refer to ROLE AUTHORIZATION DESCRIPTORS ROLE COLUMN GRANTS Information on privileges on COLUMN objects granted to or by the current session roles ROLE ROUTINE GRANTS Information on privileges on FUNCTION and PROCEDURE objects granted to or by the current session roles ROLE TABLE GRANTS Information on privileges on TABLE and VIEW objects granted to or by the current session roles ROLE UDT GRANTS Information on privileges on TYPE objects granted to or by the current session roles ROLE USAGE GRANTS Information on privileges on USAGE privileges granted to or by the current session roles ROUTINE COLUMN USAGE Information on COLUMN objects of different tables that are referenced in FUNCTION and PROCEDURE definitions ROUTINE JAR USA
215. SV vy 12008 01 01 00 00 00 Functions to Convert or Format a Datetime TIMESTAMP TIMESTAMP lt num value expr gt TIMESTAMP lt char value expr gt TIMESTAMP lt char value expr gt lt char value expr gt TIMESTAMP date value expr gt time value expr gt This function translates the arguments into a TIMESTAMP value When the single argument is a numeric value it is interpreted as a Unix timestamp in seconds A single formatted date or timestamp string is translated to a TIMESTAMP When two arguments are used the first argument is the date part and the second argument is the time part of the returned TIMESTAMP value An example including the result is given below TIMES TAMPER 0 e Sle 27 0 ee cess rev OLD TIMESTAMP 2008 11 22 20 30 40 000000 TO_CHAR TO_CHAR lt datetime valu xpr gt char value expr gt This function formats a datetime or numeric value to the format given in the second argument The format string can contain pattern elements from the list given below plus punctuation and space characters An example including the result is given below TO CHAR TIMESTAMP 2008 02 01 20 30 40 YYYY BC MONTH DAY HE 188 HyperSGL Built In Functions 2008 AD February Friday 8 TO CHAR TIMESTAMP 2008 02 01 20 30 40 The Date is YYYY BC MONTH DAY HH The Date is 2008 AD February Friday 8 The format is internally translated to a
216. Solaris super user It s a System V package Download then uncompress the package with uncompress or gunzip 252 HyperSGL HyperSQL on UNIX Installing from a BSD Port or Package Installing from a rpm file Installing from a zip file uncompress filename pkg Z You can read about the package by running pkginfo 1 d filename pkg Run pkgadd as root to install pkgadd d filename pkg You re on your own I find everything much easier when I install software to BSD without their package management systems Just skip this section if you know how to install an RPM If you found the RPM using a software management system then just have it install it The remainder of item explains a generic command line method which should work with any Linux variant After you download the rpm you can read about it by running rpm qip path to file rpm Rpms can be installed or upgraded by running rpm Uvh path to file rpm as root Suse users may want to keep Yast aware of installed packages by running rpm through Yast yast2 i path to file rpm Extract the zip file in an ancestor directory of the new HSQLDB home You don t need to create the HSQLDB_HOME directory because the extraction will create a version labelled directory and the subdirectory hsqldb This hsqldb directory is your HSQLDB HOME and you can move it to wherever you wish If you will be upgrading or maintaining multipl
217. T FROM anothertable Subquery A subquery is simply a query expression in brackets A query expression is usually a complete SELECT statement and is discussed in the rest of this chapter A scalar subquery returns one row with one column A row subquery returns one row with one or more columns A table subquery returns zero or more rows with one or more columns The distinction between different forms of subquery is syntactic Different forms are allowed in different contexts If a scalar subquery or a row subquery return more than one row an exception is raised If a scalar or row subquery returns no row it is usually treated as returning a NULL Depending on the context this has different consequences scalar subquery subquery row subquery subquery 120 HyperSGL Data Access and Change table subquery gt subquery subquery left paren query expression right paren Query Specification A query specification is also known as a SELECT statement It is the most common form of derived table A table expression is a base table a view or any form of allowed derived table The SELECT statement performs projection naming computing or aggregation on the rows of the table expression query specification SELECT DISTINCT ALL select list table expression select list asterisk lt select sublist comma l
218. T DATABASE SQL AVG SCALE numeric value By default the result of division and the AVG and MEDIAN aggregate functions has the same type as the aggregated type of the values This includes the scale The scale specified with this property is used if it is larger than the scale of the operation For example the average of 5 and 10 is 7 by default but 7 50 if the scale is specified as 2 The result of 7 3 is 2 by default but 2 33 if the scale is specified as 2 Standard SQL considers this behaviour implementation dependent Some databases use a default scale larger than zero The property is 0 by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sql avg scale SET DATABASE SQL DOUBLE NAN set database sql double nan set database sql double nan SET DATABASE SQL DOUBLE NAN TRUE FALSE When the property is TRUE division of a floating point value a DOUBLE value by zero raises an exception When the property is FALSE a Java Double NaN POSITIVE INFINITY or NEGATIVE INFINITY value is returned Standard SQL requires an exception to be raised The property is TRUE by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sq1 double nan SET DATABASE SQL NULLS FIRST set database sql nulls first set database sql nulls first SET DATABA
219. T LENGTH can be used with character binary and bit strings All functions return a BIGINT value that measures the length of the string in the given unit CHAR LENGTH counts characters OCTET LENGTH counts octets and BIT LENGTH counts bits in the string For CHAR LENGTH if USING OCTETS is specified the octet count is returned which is twice the normal length Foundation CONCAT CONCAT char value expr 1 gt char value expr 2 CONCAT binary value expr 1 binary value expr 2 gt The arguments are character strings or binary strings Returns a string formed by concatenation of the arguments Minimum number of arguments is 2 Equivalent to the SQL concatenation expression lt value expr l value expr 2 QDBC 173 HyperSGL Built In Functions DIFFERENCE DIFFERENCE char value expr 1 char value expr 2 The arguments are character strings Converts the arguments into SOUNDEX codes and returns an INTEGER between 0 4 which indicates how similar the two SOUNDEX value are If the values are the same it returns 4 if the values have no similarity it returns 0 In between values are returned for partial similarity JDBC INSERT INSERT char value expr 1 gt offset length char value expr 2 Returns a character string based on char value expr 1 gt in which length characters have been removed from the lt offset gt position
220. The value is rounded by replacing digits with zeros from lt int value expr gt places right of the decimal point to the end If int value expr gt is negative ABS int value expr gt digits to left of the decimal point and all digits to the right of the decimal points are replaced with zeros Results of calling TRUNCATE with 12345 6789 with 2 0 2 4 are 12300 12345 12345 67 12345 6789 The function does not change the number if the second argument is larger than or equal to the scale of the first argument If the second argument is not a constant when it is a parameter or column reference then the type of the return value is always the same as the type of the first argument In this case the discarded digits are replaced with zeros JDBC WIDTH_BUCKET WIDTH BUCKI ET value expr 1 gt value expr 2 lt value expr 3 int value expr gt Returns an integer value between 0 and int value expr gt 1 The initial three parameters are of the same numeric or datetime type The range lt value expr 2 lt value expr 3 isdividedinto int value expr equal sections buckets The returned integer value indicates the index of the bucket where value expr 1 can be placed If the value expr 1 falls before or after the range the return value is 0 or val 1 1 respectively lue expr This function can be used with numeric or datetime values Invalid arguments including lt int value expr gt sma
221. This allows the user to drop one of the signatures while keeping the other Routines are discussed in detail in chapter SQL Invoked Routines Indexes Indexes are an implementation defined extension to the SQL Standard HyperSQL has a dedicated name space for indexes in each schema Statements for Schema Definition and Manipulation Schemas and schema objects can be created modified and dropped The SQL Standard defines a range of statements for this purpose HyperSQL supports many additional statements especially for changing the properties of existing schema objects Common Elements and Statements These elements and statements are used for different types of object They are described here before the statements that can use them identifier definition of identifier identifier regular identifier delimited identifier SQL language identifier delimited identifier double quote character sequence double quote regular identifier special character sequence SQL language identifier special character sequence A delimited identifier is a sequence of characters enclosed with double quote symbols All characters are allowed in the character sequence A regular identifier is a special sequence of characters It consists of letters digits and the underscore characters It must begin with a letter All the letters are translated to their u
222. UNNEST SEQUENCE ARRAY CURRENT DATE 7 DAY CURRENT DATE 1 DAY 1 DAY WITH ORDINALITY SELECT i d s FROM dates LEFT OUTER JOIN costs ON dates d costs i d TED S 12 OSEE Gou 22050 077 2 5 Gonnlal 3 XH 22 9 kone e 42010 07725 Ana By XGHLIOI 226 SOAS o2 0d 0 OE OE rado PT ZOU rS xm dulb TABLE When TABLE is used in this context the collection value expression must be the result of a function call to a built in function or user defined function that returns an array or a table When the function returns an array this array is converted into a table similar to the way UNNEST operates When the function returns a table the result is a MULTISET and is used as is lt table function derived table gt TABLE lt left paren gt lt collection value expression gt lt right paren gt column name list The column list that is specified for the table reference must contain names that are unique within the list lt derived column list gt lt column name list gt column name list column name gt comma column name Jj A parenthesized joined table is simply a joined table contained in parentheses Joined tables are discussed below Xparenthesized joined table left paren parenthesized joined table right paren left paren joined table right paren Joined Table Joins are operators with two table as the operands resulting in a third table called j
223. UPDATE privileges may apply to all columns or to individual columns These privileges determine whether the lt grantee gt can execute SQL data statements on the table The SELECT privilege designates the columns that can be referenced in SELECT statements as well as the columns that are read in a DELETE or UPDATE statement including the search condition The INSERT privilege designates the columns into which explicit values can be inserted To be able to insert a row into the table the user must therefore have the INSERT privilege on the table or at least all the columns that do not have a default value The UPDATE privilege simply designates the table or the specific columns that can be updated 89 HyperSGL Access Control The REFERENCES privilege allows the grantee to define a FOREIGN KEY constraint on a different table which references the table or the specific columns designated for the REFERENCES privilege The TRIGGER privilege allows adding a trigger to the table Sequence Type Domain Character Set Collation Transliteration For these objects only USAGE can be granted The USAGE privilege is needed when object is referenced directly in an SQL statement Routine For routines including procedures or functions only EXECUTE privilege can be granted This privilege is needed when the routine is used directly in an SQL statement Other Objects Other objects such as constraints and assertions are not used d
224. XTERNAL NAME CLASSPATH org npo lib nowLessAnHour CREATE FUNCTION an_hour_before_or_now t TIMESTAMP RETURNS TIMESTAMP NO SQL LANGUAGE JAVA PARAMETER STYLE JAVA EXTERNAL NAME CLASSPATH org npo lib nowLessAnHour CREATE FUNCTION testquery i INTEGER RETURNS TABLE n VARCHAR 20 i INT READS SQL DATA LANGUAGE JAVA EXTERNAL NAME CLASSPATH org hsqldb test TestJavaFunctions getQueryResult 157 HyperSQL SQL Invoked Routines In the Java class the definitions are as follows Note the definition of the getQueryResult method begins with a java sql Connection parameter This parameter is ignored when choosing the Java method The parameter is used to pass the current JDBC connection to the Java method public static java sql Time nowLessAnHour java sql Time value public static java sql Timestamp nowLessAnHour java sql Timestamp value public static ResultSet getQueryResult Connection connection int i throws SQLException Statement st connection createStatement return st executeQuery SELECT FROM T WHERE I i Java Language Procedures Java procedures are defined similarly to functions The differences are The return type of the Java static method must be void e f a parameter is defined as OUT or INOUT the corresponding Java static method parameter must be defined as an array of the JDBC non primitive type When the Java static method is invoked
225. action deadlock or conflict is about to happen the current transaction is rolled back and an exception is raised When this property is set false the transaction is not rolled back Only the latest statement that would cause the conflict is undone and an exception is raised The property should not be changed unless the application can quickly perform an alternative statement and complete the transaction It is provided for compatibility with other database engines which do not roll back the transaction upon deadlock This command is also discussed in the Sessions and Transactions chapter Only a user with the DBA role can execute this statement This is equivalent to the connection property hsqldb tx conflict rollback SET DATABASE DEFAULT ISOLATION LEVEL set database default isolation level statement ll a ET DATABASE DEFAULT ISOLATION LEVEL set database default isolation level READ COMMITTED SERIALIZABLE 213 HyperSGL System Management Sets the transaction isolation level for new sessions The default is READ COMMITTED Each session can also set Its isolation level Only a user with the DBA role can execute this statement This is equivalent to the connection property hsgldb tx level SET DATABASE TEXT TABLE DEFAULTS set database text table defaults statement set database text table defaults statement SET DATABASE TEXT TABLE DEFAULTS character literal
226. alent to giving the world or the Internet read access to your tables you are giving read access to people that have been given accounts for the target database catalog Shutdown Doa clean database shutdown when you are finished with the database catalog You need to connect up as SA or some other Admin user of course With SglTool you can run java jar path to sqltool jar sgl shutdown localhost sa You don t have to worry about stopping the Listener because it shuts down automatically when all served database catalogs are shut down Running Hsqldb as a System Daemon You can of course run HSQLDB through inittab on System V UNIXes but usually an init script is more convenient and manageable This section explains how to set up and use our UNIX init script Our init script is only for use by root That is not to say that the Listener will run as root it usually should not The main purpose of the init script is to start up a Listener for the database catalogs specified in your server properties file and to gracefully shut down these same catalogs For each catalog defined by a server database X setting in your properties file you must define an administrative urlid in your sqltool rc these are used to access the catalogs for validation and shutdown purposes Finally you list the urlid 259 HyperSGL HyperSQL on UNIX names in your init script config file If due to firewall issues you want to run a W
227. alse the WRITE DELAY is set to 0 seconds The SQL command for this property allows more precise control over the property SET FILES WRITE DELAY TRUE FALSE lt seconds value gt lt milliseconds value gt MILLIS Table 12 51 Logging Data Change Statements Frequency Name Default Description hsqldb write_delay_millis write delay for writing log file entries 239 HyperSGL Properties Name Default Description If the property is used the WRITE DELAY property of the database is set the given value in milliseconds The SQL command for this property allows the same level of control over the property SET FILES WRITE DELAY TRUE FALSE seconds value milliseconds value MILLIS Table 12 52 Use of NIO for Disk Table Storage Name Default Description hsqldb nio_data_file use of nio access methods for the data file Setting this property to false will avoid the use of nio access methods resulting in somewhat reduced speed If the data file is larger than hsqldb nio_max_size default 256MB when it is first opened or when its size is increased nio access methods are not used Also if the file gets larger than the amount of available computer memory that needs to be allocated for nio access non nio access methods are used SET FILES NIO TRUE FALSE Table 12 53 Use of NIO for Disk Table Storage Description
228. alues they will be resolved relative to the S user dir when the JRE is started d Caution If you set any password in a properties or any other file you need to restrict access to the file On a good operating system you can do this like so chmod 600 path to server properties The values and behavior of the system settings above match the usage documented for javax net ssl keyStorePasswordand javax net ssl keyStore in the JSSE docs Note Before version 2 0 HyperSQL depended on directly setting the corresponding JSSE properties The new idiom is more secure and easier to manage If you have an old password in a UNIX init script config file you should remove it JSSE If you are running Java 4 x or later then you are all set Java 1 x users you are on your own Sun does not provide a JSSE that will work with 1 x Java 2 x and 3 x users continue Go to http java sun com products jsse index 103 html If you agree to the terms and meet the requirements download the domestic or global JSSE software All you need from the software distro is the three jar files If you have a JDK installation then move the 3 jar files into the directory JAVA HOME jre lib ext If you have a JRE installation then move the 3 jar files into the directory 7AVA HOME lib ext Pretty painless Making a Private key Keystore There are two main ways to do this Either you can use a certificate signed by a certificate
229. alues are not really a substitute for the INTERVAL type Expressions such as datecol 7 DAY gt CURRENT DATE are optimised to use indexes when it is possible while the equivalent function calls are not optimised The OTHER type is for storage of Java objects If your objects are large serialize them in your application and store them as BLOB in the database The ARRAY type supports all base types except LOB and OTHER types ARRAY data objects are held in memory while being processed It is therefore not recommended to store more than about a thousand objects in an ARRAY in normal operations with disk based databases For specialised applications use ARRAY with as many elements as your memory allocation can support HyperSQL 2 2 x has several compatibility modes which allow the type names that are used by other RDBMS to be accepted and translated into the closest SQL Standard type For example the type TEXT supported by MySQL and PostgreSQL is translated in these compatibility modes Data Types and Operations HyperSQL supports all the types defined by SQL 92 plus BOOLEAN BINARY and LOB types that were added later to the SQL Standard It also supports the non standard OTHER type to store serializable Java objects SQL is a strongly typed language All data stored in specific columns of tables and other objects such as sequence generators have specific types Each data item conforms to the type limits such as precision and scale
230. ame Default Description sql double_nan behaviour of expressions returning DOUBLE NaN This property when set false causes division of DOUBLE values by Zero to return a Double NaN value By default an exception is thrown SET DATABASE SQL DOUBLE NAN TRUE FALSE Table 12 22 Sort order of NULL values Name Default Description sql nulls_first ordering of NULL values By default nulls appear before not null values when a result set is ordered without specifying NULLS FIRST or NULLS LAST This property when set false causes nulls to appear by default after not null values in result sets with ORDER BY SET DATABASE SQL NULLS FIRST TRUE FALSE Table 12 23 String comparison with padding Name Default Description sql pad_space ordering of strings with trailing spaces 233 HyperSGL Properties Name Default Description By default when two strings are compared he shorter string is padded with spaces before comparison When this property is set false no padding takes place before comparison Without padding the shorter string is never equal to the longer one Before version 2 0 HSQLDB used NO PAD comparison If you need the old behaviour use this property when opening an older database SET DEFAULT COLLATION collation name NO PAD PAD SPACE Table 12 24 DB2 Style Syntax Name Description sql syntax_db2 support for
231. and then a type definition of DECIMAL with no precision and scale is treated as DECIMAL 100 10 In normal operation it is treated as DECIMAL 100 Integral Types In expressions TINYINT SMALLINT INTEGER BIGINT NUMERIC and DECIMAL without a decimal point are fully interchangeable and no data narrowing takes place If the SELECT statement refers to a simple column or function then the return type is the type corresponding to the column or the return type of the function For example CREATE TABLE t a INTEGER b BIGINT SELECT MAX a MAX b FROM t will return a ResultSet where the type of the first column is java lang Integer and the second column is java lang Long However SELECT MAX a 1 MAX b 1 FROM t will return java lang Long and BigDecimal values generated as a result of uniform type promotion for all the return values Note that type promotion to BigDecimal ensures the correct value is returned if MAX b evaluates to Long MAX VALUE There is no built in limit on the size of intermediate integral values in expressions As a result you should check for the type of the ResultSet column and choose an appropriate get XXXX method to retrieve it Alternatively you can use the getObject method then cast the result to java lang Number and use the intValue or longValue methods on the result When the result of an expression is stored in a column of a database table it has to fit in the
232. and Handling of Java Objects Any serializable JAVA Object can be inserted directly into a column of type OTHER using any variation of PreparedStatement setObject methods For comparison purposes and in indexes any two Java Objects are considered equal unless one of them is NULL You cannot search for a specific object or perform a join on a column of type OTHER Please note that HSQLDB is not an object relational database Java Objects can simply be stored internally and no operations should be performed on them other than assignment between columns of type OTHER or tests for NULL Tests such as WHERE objectl object2 do not mean what you might expect as any non null object would satisfy such a tests But WHERE objectl IS NOT NULL is perfectly acceptable The engine does not allow normal column values to be assigned to Java Object columns for example assigning an INTEGER or STRING to such a column with an SQL statement such as UPDATE mytable SET objectcol intcol WHERE lt java object type gt OTHER Type Length Precision and Scale In older version of HyperSQL all table column type definitions with a column length precision or scale qualifier were accepted and ignored HSQLDB 1 8 enforced correctness but included an option to enforce the length precision or scale In HyperSQL 2 0 length precision and scale qualifiers are always enforced For backward compatibility when olde
233. and if there is a match an exception is thrown The setting FALSE makes the behaviour more restrictive For example inserting 1 null twice is possible by default but not possible when the property is FALSE Setting this property FALSE results in UNIQUE constraint behaviour similar to Oracle SQL Standard requires the default TRUE behaviour The property is TRUE by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sql unique nulls SET DATABASE SQL CONVERT TRUNCATE set database sql unique convert truncate set database sql convert truncate statement TRUNCATE TRUE FALSE ET DATABASE E SOL CONVI I ERT When the property is TRUE conversion from a floating point value a DOUBLE value to an integral type always truncates the fractional part When the property is FALSE rounding takes place instead of truncation For example assigning the value 123456E 2 to an integer column will result in 1234 by default but 1235 when the property is FALSE 217 HyperSGL System Management Standard SQL considers this behaviour implementation dependent The property is TRUE by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sql convert trunc SET DATABASE SQL AVG SCALE set database sql avg scale set database sql avg scale SE
234. and the constraint is a UNIQUE constraint which is referenced by a FOREIGN KEY constraint on another table then the FOREIGN KEY constraint is also dropped DROP DOMAIN drop domain statement drop domain statement DROP DOMAIN domain name drop behavior Destroy a domain If drop behavior is CASCADE it works differently from most other objects If a table features a column of the specified DOMAIN the column survives and inherits the DEFAULT CLAUSE and the CHECK CONSTRAINT of the DOMAIN Trigger Creation 64 HyperSGL Schemas and Database Objects CREATE TRIGGER trigger definition trigger definition CREATE TRIGGER trigger name trigger action time trigger event ON table name REFERENCING transition table or variable list triggered action Ti D Hj H lt trigger action time gt BEFORE ER INSTEAD OF lt trigger event gt INSERT DELETE UPDATE OF lt trigger column list gt lt trigger column list gt lt column name list gt lt triggered action gt FOR EACH ROW STATEMENT lt triggered when clause gt lt triggered SQL statement gt lt triggered when clause gt WHEN lt left paren gt lt search condition gt lt right paren gt lt triggered SQL statement gt lt SQL procedure statement gt BEGIN ATOMIC lt SQL procedure statement gt lt semicolon gt
235. ans as a value of DOUBLE type JDBC COT COT num value expr gt Returns the cotangent of the argument as a value of DOUBLE type The num value expr gt represents an angle expressed in radians JDBC DEGREES DEGREES num value expr gt Converts the argument an angle expressed in radians into degrees and returns the value in the DOUBLE type JDBC EXP EXP num value expr gt Returns the exponential value of the argument as a value of DOUBLE type JDBC and Foundation FLOOR FLOOR num value expr gt 179 HyperSGL Built In Functions Returns the largest integer that is less than or equal to the argument If the argument is exact numeric then the result is exact numeric with a scale of 0 If the argument is approximate numeric then the result is of DOUBLE type JDBC and Foundation LN LN num value expr gt Returns the natural logarithm of the argument as a value of DOUBLE type Foundation LOG LOG num value expr gt Returns the natural logarithm of the argument as a value of DOUBLE type JDBC LOG10 LOG10 lt num value expr gt Returns the base 10 logarithm of the argument as a value of DOUBLE type JDBC MOD num value expr 1 gt num value expr 2 MOD Returns the remainder modulus of lt num value expr 1 gt divided by lt num value expr 2 gt The data type of the returned value is the same as the second argument JDBC and Found
236. argument value expression target specification Invoke an SQL invoked routine Examples are given in the SQL Invoked Routines chapter COLLATE collate clause collate clause COLLATE collation name Specify a collation for a column or for an ORDER BY expression This collation is used for comparing the values of the column in different rows Comparison can happens during the execution of SELECT UPDATE or DELETE statements when a UNIQUE constraint or index is defined on the column or when the the rows are sorted by an ORDER BY clause CONSTRAINT constraint name definition constraint name definition CONSTRAINT constraint name Tj ca constraint characteristics constraint check time NOT DEFERRABLE NOT DEFERRABLE constraint check time Li constraint check time INITIALLY DEFERRED INITIALLY IMMEDIAT Specify the name of a constraint and its characteristics This is an optional element of CONSTRAINT definition not yet supported by HyperSQL 118 HyperSGL Data Access and Change Data Access Statements HyperSQL fully supports all of SQL 92 data access statements plus some additions from SQL 2008 Due to time constraints the current version of this Guide does not cover the subject fully You are advised to consult an SQL book such as the recent O Reilly title SQL and Relational Theory by C
237. art value gt lt signed numeric literal gt 69 HyperSGL Schemas and Database Objects Change the definition of a named sequence generator The same options that are used in the definition of the SEQUENCE can be used to alter it The exception is the option for the start value which is RESTART WITH for the ALTER SEQUENCE statement If RESTART is used by itself without a value then the current value of the sequence is reset to the start value Otherwise the current value is reset to the given restart value DROP SEQUENCE drop sequence generator statement drop sequence generator statement DROP SEQUENCE IF EXISTS sequence generator name IF EXISTS drop behavior Destroy an external sequence generator If the drop behavior is CASCADE then all objects that reference the sequence are dropped These objects can be VIEW ROUTINE or TRIGGER objects SQL Procedure Statement SQL procedure statement SQL procedure statement The definition of CREATE TRIGGER and CREATE PROCEDURE statements refers to SQL procedure statement The definition of this element is given below However only a subset of these statements are allowed in trigger or routine definition SQL procedure statement SQL executable statement SQL executable statement SQL schema statement SQL data statement SQL control statement SQL transaction statement SQL connection state
238. as Identifier Name Default Description sql enforce names enforcing SQL keywords This property when set true prevents SQL keywords being used for database object names such as columns and tables SET DATABASE SQL NAMES TRUE FALSE Table 12 11 SQL Keyword Starting with the Underscore or Containing Dollar Characters Name Description sql regular names enforcing SQL keywords This property when set true prevents database object names such as columns and tables beginning with the underscore or containing the dollar character SET DATABASE SQL REGULAR NAMES TRUE FALSE Table 12 12 Reference to Columns Names Name Default Description sql enforce refs enforcing column reference disambiguation This property when set true causes an error when an SQL statement usually a select statement contains column references that can be resolved by more than one table name or alias In effect forces such column references to have a table name or table alias qualifier SET DATABASE SQL REFERENCES TRUE FALSE Table 12 13 String Size Declaration Name Default Description sql enforce size size enforcement of string columns Conforms to SQL standards for size and precision of data types When true all VARCHAR column type declarations require a size When the property is false and there is no size in the declaration a default size is u
239. as SYSDATE and SYSTIMESTAMP and more complex ones such as TO DATE and TO CHAR Non standard data type definitions such as NUMBER VARCHAR2 NVARCHAR2 BINARY DOUBLE BINARY FLOAT LONG RAW are translated into the closest HyperSQL SQL Standard equivalent in ORA mode The DATE type is interpreted as TIMESTAMP O in ORA syntax mode The DUAL table and the expressions ROWNUM CURRVAL NEXTVAL are supported in ORA syntax mode HyperSQL natively supports operations involving datetime and interval values These features are based on the SQL Standard Many subtle automatic type conversions syntax refinements and other common features are supported SQL routines are generally portable but some changes may be required DB2 Compatibility DB2 is highly compatible with the SQL Standard except its lack of support for the INFORMATION SCHEMA Applications can be ported to HyperSQL without difficulty 208 HyperSGL System Management Use set database sql syntax DB2 statement to enable support for some non standard syntax of DB2 Use MVCC with set database transaction control statement if your application is multi user HyperSQL supports almost the entire syntax of DB2 together with many of the functions Even local temporary tables using the SESSION pseudo schema are supported The DB2 binary type definition FOR BIT DATA as well as empty definition of column default values are supported in DB2 syntax mode Many DB2 functi
240. as trigName argument the name of the table as tabName argument the OLD ROW as oldRow argument and the NEW ROW as newRow argument The oldRow argument is null for row level INSERT triggers The newRow argument is null for row level DELETE triggers For table level triggers both arguments are null that is there is no access to the data The triggerType argument is one of the constants in the org hsqldb Trigger interface which indicate the type of trigger for example INSERT BEFORE ROW or UPDATE AFTER ROW The Java class for the trigger can be reused for several triggers on different tables The method code can distinguish between the different tables and triggers using the supplied arguments and take appropriate action fire int triggerType String name String table Object rowl Object row2 The Java method for a synchronous trigger see below can modify the values in newRow2 in a BEFORE trigger Such modifications are reflected in the row that is being inserted or updated Any other modifications are ignored by the engine A Java trigger that uses an instance of org hsqldb Trigger has two forms synchronous or asynchronous immediate or queued By default or when QUEUE 0 is specified the action is performed immediately by calling the Java method This is similar to SQL trigger actions When QUEUE n is specified with n larger than 0 the engine uses a separate thread to execute the Java method using a queue with the s
241. ases not all the columns are necessary for the intended operation If the statement is in the form SELECT FROM joined table then all the columns of joined table are returned But normally the columns to be returned are specified after the SELECT keyword separated from each other with commas Computed Columns In the select list itis possible to use expressions that reference any columns of joined table Each of these expressions forms a computed column It is computed for each row of the result table using the values of the columns of the joined table for that row Naming Naming is used to hide the original names of tables or table columns and to replace them with new names in the scope of the query Naming is also used for defining names for computed columns Without explicit naming the name of a column is a predefined name If the column is a column of a table or is a named parameter the name is of the table column or parameter is used Otherwise it is generated by the database engine HyperSQL generates column names such as Cl C2 etc As generated naming is implementation defined according to the SQL Standard it is better to explicitly name the computed and derived columns in your applications Naming in Joined Table Naming is performed by adding a new name after a table s real name and by adding a list of column names after the new table name Both table naming and column naming are optional but table naming is
242. at are shared Simultaneous access to these resources can reduce the overall efficiency of the system MEMORY and TEXT tables do not share resources and do not block multi threaded access With CACHED tables each row change operation blocks the file and its cache momentarily until the operation is finished This is done separately for each row therefore a multi row INSERT UPDATE or DELETE statement will allow other sessions to access the file during its execution With CACHED tables SELECT operations do not block each other but selecting from different tables and different parts of a large table causes the row cache to be updated frequently and will reduce overall performance The new access pattern is the opposite of the access pattern of version 1 8 x In the old version even when 20 sessions are actively reading and writing only a single session at a time performs an SQL statement completely before the next session is allowed access In the new version while a session is performing a SELECT statement and reading rows of a CACHED table to build a result set another session may perform an UPDATE statement that reads and writes rows of the same table The two operations are performed without any conflict but the row cache is updated more frequently than when one operation is performed after the other operation has finished Viewing Sessions As HyperSQL is multithreaded you can view the current sessions and their state from any admin session T
243. atabase and accessed transparently In addition a HyperSQL server supports multiple separate databases In MySQL older non standard forms of database object name case sensitivity make is difficult to port applications Use the latest form which encloses case sensitive names in double quotes MySQL functions are generally supported including GROUP CONCAT For fine control over type conversion check the settings for set database sql convert truncate statement If you use concatenation of possibly NULL values in your select statements you may need to change the setting with the set database sql concat nulls statement MySQL supports most SQL Standard types except INTERV AL types as well as non standard types which are also supported by HyperSQL Supported types include SMALLINT INT BIGINT DOUBLE FLOAT DECIMAL NUMERIC VARCHAR CHAR BINARY VARBINARY BLOB DATE TIMESTAMP all Standard SQL and TINYINT DATETIME non Standard MySQL uses a non standard expression SELECT A Test String toreturna single row table The standard form is VALUES A Test String In MYS syntax mode this type of SELECT is supported SQL user defined function and procedure syntax is very similar to SQL Standard syntax A few changes may still be required 207 HyperSGL System Management Firebird Compatibility Firebird generally follows the SQL Standard Applications can be ported to HyperSQL without difficulty Apac
244. atabase file path is opt db testdb If you create an identical directory structure on the C drive of a Windows host you can use the same URL in both Windows and Linux Connection c DriverManager getConnection jdbc hsqldb file opt db testdb SA When using relative paths these paths will be taken relative to the directory in which the shell command to start the Java Virtual Machine was executed Refer to the Javadoc for JDBCConnection for more details Paths and database names for file databases are treated as case sensitive when the database is created or the first connection is made to the database But if a second connection is made to an open database using a path and name that differs only in case then the connection is made to the existing open database This measure is necessary because in Windows the two paths are equivalent A mem database is specified by the mem protocol For mem databases the path is simply a name Several mem databases can exist at the same time and distinguished by their names In the example below the database is called mymemdb Connection c DriverManager getConnection jdbc hsqldb mem mymemdb SA A res database is specified by the res protocol As itis a Java resource the database path is a Java URL similar to the path to a class In the example below resdb is the root name of the database files which exists in the directory org my path within th
245. ated It is internally translated to a special CREATE FUNCTION statement where the name of the function is the double quoted fully qualified name of the Java method used Securing Access to Classes By default the static methods of any class that is on the classpath are available to be used This can compromise security in some systems The optional Java system property hsqldb method class names allows preventing access to classes other than java lang Math or specifying a semicolon separated list of allowed classes A property value that ends with is treated as a wild card and allows access to all class or method names formed by substitution of the asterisk In the example below the property has been included as an argument to the Java command java Dhsqldb method class names org me MyClass org you YourClass org you lib the rest of the command line 160 HyperSQL SQL Invoked Routines The above example allows access to the methods in the two classes org me MyClass and org you YourClass together with all the classes in the org you lib package Note that if the property is not defined no access control is performed at this level Once the routine has been defined the normal database access control still applies The routine can be executed only by the users who have been granted EXECUTE privileges on it The user who executes a Java routine must also have the relevant access privileges on the tab
246. atement gt lt if statement gt lt while statement gt lt repeat statement gt lt for statement gt lt loop statement gt lt iterate statement lt leave statement gt lt signal statement gt lt resignal statement gt lt return statement gt lt select statement single row gt open statement The following SQL Statements can be used in procedures but not in generally in functions they can be used in functions only to change the data in a local table variable These statements are covered in other chapters of this Guide call statement delete statement 144 HyperSQL SQL Invoked Routines insert statement gt update statement merge statement As shown in the examples below the formal parameters and the variables of the routine can be used in statements similar to the way a column reference is used Compound Statement A compound statement is enclosed in a BEGIN END block with optional labels It can contain one or more SOL variable declaration declare cursor gt or lt handler declaration before at least one SQL statement The BNF is given below lt compound statement gt lt beginning label gt lt colon gt BEGIN NOT ATOMIC lt SQL variable declaration gt lt semicolon gt lt declare cursor gt lt semicolon gt lt handler declaration gt lt semicolon gt lt SQL procedure statement gt l
247. atetime and Interval Operations An interval can be added to or subtracted from a datetime value so long as they have some fields in common For example an INTERVAL MONTH cannot be added to a TIME value while an INTERVAL HOUR TO SECOND can The interval is first converted to a numeric value then the value is added to or subtracted from the corresponding field of the datetime value If the result of addition or subtraction is beyond the permissible range for the field the field value is normalised and carried over to the next significant field until all the fields are normalised For example adding 20 minutes to TIME 23 50 10 will result successively in 23 70 10 24 10 10 and finally TIME 00 10 10 Subtracting 20 minutes from the result is performed as follows 00 10 10 1 50 10 finally TIME 23 50 10 Note that if DATE or TIMESTAMP normalisation results in the YEAR field value out of the range 1 1000 then an exception condition is raised If an interval value based on MONTH is added to or subtracted from a DATE or TIMESTAMP value the result may have an invalid day 30 or 31 for the given result month In this case an exception condition is raised The result of subtraction of two datetime expressions is an interval value The two datetime expressions must be of the same type The type of the interval value must be specified in the expression using only the interval field names The two datetime expressions are enclosed in par
248. ation PI PI Returns the constant pi as a value of DOUBLE type JDBC POWER POWER lt num value expr 1 gt lt num value expr 2 gt Returns the value of num value expr 1 raised to the power of int value expr 2 asa value of DOUBLE type JDBC and Foundation RADIANS RADIANS num value expr gt Converts the argument an angle expressed in degrees into radians and returns the value in the DOUBLE type JDBC RAND RAND lt int value expr gt Returns a random value in the DOUBLE type The optional int value expr gt is used as seed value In HyperSQL each session has a separate random number generator The first call that uses a seed parameter sets the seed for subsequent calls that do not include a parameter JDBC ROUND 180 HyperSGL Built In Functions ROUND num value expr int value expr gt The num value expr gt is of the DOUBLE type or DECIMAL type The function returns a DOUBLE or DECIMAL value which is the value of the argument rounded to int value expr gt places right of the decimal point If int value expr gt is negative the first argument is rounded to int value expr places to the left of the decimal point This function rounds values ending with 5 or larger away from zero for DECIMAL arguments and results When the value ends with 5 or larger and the argument and result are DOUBLE It rounds the value towards the closest even value The datetim
249. authority or you can make your own One thing that you need to know in both cases is the Common Name of the cert has to be the exact hostname that JDBC clients will use in their database URL CA Signed Cert I m not going to tell you how to get a CA signed SSL certificate That is well documented at many other places Assuming that you have a standard pem style private key certificate here s how you can use openssl http www openssl org and the program DERImport to get it into a JKS keystore Because I have spent a lot of time on this document already I am just giving you an example Example 13 4 Getting a pem style private key into a JKS keystore openssl pkcs8 topk8 outform DER in Xpvk pem inform PEM out Xpvk pk8 nocrypt 249 HyperSGL HyperSQL Network Listeners Servers openssl x509 in Xcert pem out Xcert der outform DER java DERImport new keystore NEWALIAS Xpvk pk8 Xcert der Important Make sure to set the password of the key exactly the same as the password for the keystore You need the program DERImport class of course Do some internet searches to find DERImport java or DERImport class and download it If DERImport has become difficult to obtain I can write a program to do the same thing just let me know Non CA Signed Cert Run man keytoolorsee the Creating a Keystore section of JSSERefGuide html http java sun com javase 6 docs technotes guides security
250. ay refuse the connection attempt A java sql Connection object has some methods that return further java sql objects All these objects belong to the connection that returned them and are closed when the connection is closed These objects can be reused but if they are not needed after performing the operations they should be closed A java sql DatabaseMetaData object is used to get metadata for the database A java sql Statement object is used to execute queries and data change statements A java sql Statement can be reused to execute a different statement each time A java sql PreparedStatement object is used to execute a single statement repeatedly The SQL statement usually contains parameters which can be set to new values before each reuse When a java sql PreparedStatement object is created the engine keeps the compiled SQL statement for reuse until the java sql PreparedStatement object is closed As a result repeated use of a java sql PreparedStatement is much faster than using a java sql Statement object A java sql CallableStatement object is used to execute an SQL CALL statement The SQL CALL statement may contain parameters which should be set to new values before each reuse Similar to java sql PreparedStatement the engine keeps the compiled SQL statement for reuse until the java sql CallableStatement object is closed A java sql Connection object also has some methods for transaction control The commi
251. b jar org hsqldb server Server Alternatively you can specify the path of the server properties file on the command line In this case the properties file can have any name or extension but it should be a valid properties file java cp lib hsqldb jar org hsqldb server Server props myserver props Use the help argument to see the list of available arguments java cp lib hsqldb jar org hsqldb server Server help The contents of the server properties file is described in the next section HyperSQL HTTP Server This method of access is used when the computer hosting the database server is restricted to the HTTP protocol The only reason for using this method of access is restrictions imposed by firewalls on the client or server machines and it should not be used where there are no such restrictions The HyperSQL HTTP Server is a special web server that allows JDBC clients to connect via HTTP The server can also act as a small general purpose web server for static pages To run an HTTP server replace the main class for the server in the example command line above with the following java cp lib hsqldb jar org hsqldb server WebServer 243 HyperSGL HyperSQL Network Listeners Servers The contents of the server properties file is described in the next section HyperSQL HTTP Servlet This method of access also uses the HTTP protocol It is used when a separate servlet engine or app
252. between different types of connection The common driver identifier is jdbc hsqldb followed by a protocol identifier mem file res hsql http hsqls https then followed by host and port identifiers in the case of servers then followed by database identifier Additional property value pairs can be appended to the end of the URL separated with semicolons Table 12 1 Memory Database URL Driver and Protocol Host and Port Example Database Example Lowercase single word identifier creates the in memory database when the first connection is made Subsequent use of the same Connection URL connects to the existing DB The old form for the URL jdbc hsqldb creates or connects to the same database as the new form for the URL jdbc hsqldb mem Table 12 2 File Database URL Driver and Protocol Host and Port Example Database Example jdbc hsqldb file not available accounts opt db accounts C data mydb The file path specifies the database files It should consist of a relative or absolute path to the directory containing the database files followed by a and the database name In the above examples the first one refers to a set of mydb files in the directory where the javacommand for running the application was issued The second and third examples refer to absolute paths on the host machine For example files named accounts in the directory opt db for the accounts database Table 12 3 Resource Da
253. c DriverManager getConnection jdbc hsqldb hsqls localhost xdb SA Connection c DriverManager getConnection jdbc hsqldb https localhost xdb SA The security features are discussed in detail in the HyperSQL Network Listeners Servers chapter Using Multiple Databases A server can provide connections to more than one database In the examples above more than one set of database names can be specified on the command line It is also possible to specify all the databases in a properties file instead of the command line These capabilities are covered in the HyperSQL Network Listeners Servers chapter Accessing the Data As shown so far a java sql Connection object is always used to access the database But the speed and performance depends on the type of connection HyperSGL Running and Using HyperSQL Establishing a connection and closing it has some overheads therefore it is not good practice to create a new connection to perform a small number of operations A connection should be reused as much as possible and closed only when it is not going to be used again for a long while Reuse is more important for server connections A server connection uses a TCP port for communications Each time a connection is made a port is allocated by the operating system and deallocated after the connection is closed If many connections are made from a single client the operating system may not be able to keep up and m
254. can be called from an SQL trigger So it is possible to define the Java function to perform any external communication that are necessary for the trigger and use SQL code for checks and alterations to data CREATE TRIGGER t BEFORE UPDATE ON customer REFERENCING NEW AS newrow FOR EACH ROW BEGIN ATOMIC IF LENGTH newrow firstname 10 THEN CALL my java function newrow firstname newrow lastname 168 HyperSGL Triggers END IF END Trigger Creation CREATE TRIGGER trigger definition trigger definition CREATE TRIGGER trigger name trigger action time trigger event ON table name BEFORE other trigger name REFERENCING transition table or variable list triggered action trigger action time BEFORE AFTER INSTEAD OF trigger event INSERT DELETE UPDATE OF trigger column list trigger column list column name list triggered action FOR EACH ROW STATEMENT triggered when clause triggered SQL statement triggered when clause WHEN left paren search condition right paren triggered SQL statement SQL procedure statement BEGIN ATOMIC SQL procedure statement lt semicolon gt END QUEUE integer literal NOWAIT CALL HSQLDB trigger class FON transition table or variable list transiti
255. ce 3 x You can simply replace the jar with an HSQLDB version 2 2 9 jar to use the latest capabilities with external databases It is not yet possible to create and use embedded databases with this version HSQLDB version 2 x jar will hopefully be included in the future versions of ApacheOpenOffice and LibreOffice Using OpenOffice LibreOffice as a Database Tool OpenOffice is a powerful database front end If you want to create schemas edit tables edit the database contents manually design and produce well formatted reports then OpenOffice is probably the best open source tools currently available To connect from OpenOffice to your database first run a local server instance for the database This is describes in the Network Listeners chapter of this guide When you connect from OpenOffice org you must specify connection to an external database and use the URL property default schema true For example the URL to connect the local database may be like jdbc hsqldb hsql localhost mydb default_schema true The only current limitation is that OpenOffice only works with the PUBLIC schema This limitation will hopefully disappear in the future versions of OOo There wil hopefuly be a version 2 x jar in the future versions of OpenOffice Converting odb files to use with HyperSQL Server You may already have an OOo database file which you want to use outside OOo or as a server database The file is in fact in the standard Z
256. character value function 109 CHAR function 173 CHECK CONSTRAINT ROUTINE USAGE 76 CHECK CONSTRAINTS 75 CHECK constraint 57 CHECKPOINT 211 COALESCE expression 106 COALESCE function 191 COLLATE 118 COLLATIONS 76 COLUMN_COLUMN_USAGE 76 COLUMN_DOMAIN_USAGE 76 COLUMN_PRIVILEGES 76 COLUMN_UDT_USAGE 76 column definition 53 column name list 124 column reference 104 COLUMNS 76 COMMENT 51 COMMIT 38 comparison predicate 111 CONCAT function 173 CONSTRAINT 118 CONSTRAINT_COLUMN_USAGE 76 CONSTRAINT_TABLE_USAGE 76 CONSTRAINT table constraint 55 CONSTRAINT name and characteristics 55 contextually typed value specification 104 CONVERT function 192 COS function 179 COT function 179 CREATE_SCHEMA ROLE 88 CREATE AGGREGATE FUNCTION 161 302 HyperSQL General Index CREATE ASSERTION 73 CREATE CAST 71 CREATE CHARACTER SET 72 CREATE COLLATION 72 CREATE DOMAIN 63 CREATE FUNCTION 139 CREATE INDEX 70 CREATE PROCEDURE 139 CREATE ROLE 91 CREATE SCHEMA 51 CREATE SEQUENCE 68 CREATE TABLE 52 CREATE TRANSLATION 72 CREATE TRIGGER 64 169 CREATE TYPE 71 CREATE USER 90 CREATE VIEW 62 CROSS JOIN 125 CRYPT_KEY function 193 CURDATE function 183 CURRENT_CATALOG function 195 CURRENT_DATE function 183 CURRENT_ROLE function 194 CURRENT_SCHEMA function 195 CURRENT_TIME function 183 CURRENT_TIMESTAMP function 183 CURRENT_USER function 194 CURRENT VALUE FOR 1
257. che Persistence and Files Settings These statements control the memory and other settings for database persistence SET FILES BACKUP INCREMENT set files backup increment statement set files backup increment statement SET FILES BACKUP INCREMENT TRUE FALSE Older versions of HSQLDB perform a backup of the data file before its contents are modified and the whole data file is saved in a compressed form when a CHECKPOINT or SHUTDOWN is performed This takes a long time when the size of the database exceeds 100 MB or so on an average 2010 computer you can expect a backup speed of 20MB per second or more The alternative is backup in increments just before some part of the data file is modified In this mode no backup is performed at CHECKPOINT or SHUTDOWN This mode is preferred for large databases which are opened and closed frequently The default mode is TRUE If the old method of backup is preferred the mode can be set FALSE Warning The old non incremental setting FALSE shouldn t be used at all when the data file is larger than 4GB If it is used the data file is not fully backed up and can result in corruption The zip compression method is used in this mode and it is limited to 4GB size Only a user with the DBA role can execute this statement This is equivalent to the connection property hsgldb inc backup SET FILES CACHE ROWS set files cache rows statement set files cache ro
258. cked against all the constraints that have been declared on the table The whole INSERT operation fails if any row fails to inserted due to constraint violation Examples INSERT INTO T DEFAULT VALUES all columns of T have DEFAULT clauses INSERT INTO T SELECT FROM Z table Z has the same columns as table T 133 HyperSGL Data Access and Change INSERT INTO T A B VALUES 1 2 3 NULL DEFAULT 6 three rows are inserted into table T e INSERT INIO T VALUES 3 ARRAYI Hot cold If the table contains an IDENTITY column the value for this column for the last row inserted by a session can be retrieved using a call to the IDENTITYO function This call returns the last value inserted by the calling session When the insert statement is executed with a JDBC Statement or PreparedStatement method the getGeneratedKeys method of Statement can be used to retrieve not only the IDENTITY column but also any GENERATED computed column or any other column The getGeneratedKeys returns a ResultSet with one or more columns This contains one row per inserted row and can therefore return all the generated columns for a multi row insert There are three methods of specifying which generated keys should be returned The first method does not specify the columns of the table With this method the returned ResultSet will have a column for each column of the table that is defined as GENERATED AS IDENTITY or GENERATED AS
259. co existence of ROLE and USER objects results in complexity With the addition of ROLE objects there is no rationale other than legacy support for granting privileges to USER objects directly It is better to create roles and grant privileges to them then grant the roles to USER objects The Standard effectively defines a special ROLE named PUBLIC All authorization have the PUBLIC role which cannot be removed from them Therefore any access right assigned to the PUBLIC role applies to all authorizations in the database For many simple databases it is adequate to create a single non admin user then assign access rights to the pre existing PUBLIC role Access to INFORMATION_SCHEMA views is granted to PUBLIC therefore these views are accessible to all However the contents of each view depends on the ROLE or USER AUTHORIZATION that is in force while accessing the view Each schema has a single AUTHORIZATION This is commonly known as the owner of the schema All the objects in the schema inherit the schema owner The schema owner can add objects to the schema drop them or alter them 87 HyperSGL Access Control By default the objects in a schema can only be accessed by the schema owner The schema owner can grant access rights on the objects to other users or roles authorization identifier authorization identifier authorization identifier role name user name Authorization identifiers share the same
260. column or the default collation of the database is used An ORDER BY operation can sometimes be optimised by the engine when it can use the same index for accessing the table data and ordering Optimisation can happen both with DESC NULLS LAST and ASC NULLS FIRST sort specification list sort specification list sort specification list value expression ASC DESC NULLS FIRST NULLS LAST Specify a sort order A sort operation is performed on the result of a query expression or query Specification and sorts the result according to one or more value expression The value expression is usually a single column of the result but in some cases it can be a column of the table expression that is not used in the select list The default is ASC and NULLS FIRST Slicing A different form of limiting the rows can be performed on the result table after it has been formed according to all the other operations selection grouping ordering etc This is specified by the FETCH ROWS and OFFSET clauses of a SELECT statement In this form the specified OFFSET rows are removed from start of the table then up to the specified FETCH rows are kept and the rest of the rows are discarded result offset clause OFFSET offset row count ROW ROWS fetch first clause FETCH FIRST NEXT fetch first row count ROW ROWS ONLY USING INDEX limit clause LIMIT
261. connection property shutdown true can be specified on the first connection to the database the connection that opens the database to force a shutdown when the last connection closes HyperSGL Running and Using HyperSQL Example 1 4 specifying a connection property to shutdown the database when the last connection is closed Connection c DriverManager getConnection jdbc hsgldb file opt db testdb shutdown true SA This feature is useful for running tests where it may not be practical to shutdown the database after each test But it is not recommended for application programs Creating a New Database When a server instance is started or when a connection is made to an in process database a new empty database is created if no database exists at the given path With HyperSQL 2 0 the username and password that are specified for the connection are used for the new database Both the username and password are case sensitive The exception is the default SA user which is not case sensitive If no username or password is specified the default SA user and an empty password are used This feature has a side effect that can confuse new users If a mistake is made in specifying the path for connecting to an existing database a connection is nevertheless established to a new database For troubleshooting purposes you can specify a connection property ifexists t rue to allow connection to an existing database o
262. ction the result is converted to an interval type that contains all the fields of the two original types An interval value can be multiplied or divided by a numeric value Again the value is converted to a numeric which is then multiplied or divided before converting back to the original interval type An interval value is negated by simply prefixing with the minus sign Interval values used in expressions are either typed values including interval literals or are interval casts The expression expression interval qualifier isa cast of the result of the expression into the INTERVAL type specified by the lt interval qualifier The cast can be formed by adding the keywords and parentheses as follows CAST expression AS INTERVAL interval qualifier Th xamples below feature different forms of expression that represent an interval value which is then added to the given date literal DATE 2000 01 01 INTERVAL 1 10 YEAR TO MONTH interval literal DATE 2000 01 01 1 10 YEAR TO MONTH the string 1 10 is cast into INTERVAL YEAR TO MONTH n DATE 2000 01 01 22 MONTH the integer 22 is cast into INTERVAL MONTH same value as above wy DATE 2000 01 01 22 DAY the integer 22 is cast into INTERVAL DAY DATE 2000 01 01 COL2 the type of COL2 must be an INTERVAL type DATE 2000 01 01 COL2 MONTH COL2 may be a number it is cast into a MONTH interval D
263. ctionColumns getFunctions and getProcedures SYSTEM PROPERTIES Contains the current values of all the database level properties Settings such as SQL rule enforcement database transaction model and default transaction level are all reported in this view The names of the properties are listed in the Properties chapter together with the corresponding SQL statements used to change the properties SYSTEM SCHEMAS For DatabaseMetaData getSchemas SYSTEM SEQUENCES SYSTEM SESSIONINFO Information on the settings and properties of the current session SYSTEM SESSIONS 80 HyperSGL Schemas and Database Objects Information on all open sessions in the database when used by a DBA user or just the current session SYSTEM TABLES Information on tables and views for DatabaseMetaData getTables SYSTEM TABLETYPES For DatabaseMetaData getTableTypes SYSTEM TEXTTABLES Information on the settings of each text table SYSTEM TYPEINFO For DatabaseMetaData getTypeInfo SYSTEM UDTS For DatabaseMetaData getUDTs SYSTEM USERS Contains the list of all users in the database when used by a DBA user or just the current user SYSTEM VERSIONCOLUMNS For DatabaseMetaData getVersionColumns 81 HyperSGL Chapter 5 Text Tables Text Tables as a Standard Feature of Hsqldb Bob Preston The HSQL Development Group Fred Toussi The HSQL Development Group Revision 4903 Copyright 2002 2012 Bob Preston and Fred Toussi Permission is
264. ctions and has no effect on the future transactions after the next transaction characteristics transaction characteristics transaction characteristics transaction mode comma transaction mode 36 HyperSGL Sessions and Transactions transaction mode isolation level transaction access mode diagnostics size transaction access mode READ ONLY READ WRITE isolation level ISOLATION LEVEL level of isolation level of isolation READ UNCOMMITTED READ COMMITTED REPEATABLE READ SERIALIZABLE diagnostics size DIAGNOSTICS SIZE number of conditions number of conditions simple value specification Specify transaction characteristics Example 3 3 Setting Transaction Characteristics SET TRANSACTION READ ONLY SET TRANSACTION ISOLATION LEVEL SERIALIZABLE SET TRANSACTION READ WRITE ISOLATION LEVEL READ COMMITTED SET CONSTRAINTS set constraints mode statement set constraints mode statement SET CONSTRAINTS constraint name list DEFERRED IMMEDIATE constraint name list ALL constraint name comma constraint name Fesa If the statement is issued during a transaction it applies to the rest of the current transaction If the statement is issued when a transaction is not active then it applies only to the ne
265. current user ASSERTIONS Empty view as ASSERTION objects are not yet supported AUTHORIZATIONS Top level information on USER and ROLE objects in the database CHARACTER SETS List of supported CHARACTER SET objects CHECK CONSTRAINTS 75 HyperSGL Schemas and Database Objects Additional information specific to each CHECK constraint including the search condition CHECK CONSTRAINT ROUTINE USAGE Information on FUNCTION objects referenced in CHECK constraints search conditions COLLATIONS Information on collations supported by the database COLUMNS Information on COLUMN objects in TABLE and VIEW definitions COLUMN COLUMN USAGE Information on references to COLUMN objects from other GENERATED COLUMN objects COLUMN DOMAIN USAGE Information on DOMAIN objects used in type definition of COLUMN objects COLUMN PRIVILEGES Information on privileges on each COLUMN object granted to different ROLE and USER authorizations COLUMN UDT USAGE Information on distinct TYPE objects used in type definition of COLUMN objects CONSTRAINT COLUMN USAGE Information on COLUMN objects referenced by CONSTRAINT objects in the database CONSTRAINT TABLE USAGE Information on TABLE and VIEW objects referenced by CONSTRAINT objects in the database DATA TYPE PRIVILEGES Information on top level schema objects of various kinds that reference TYPE objects DOMAINS Top level information on DOMAIN objects in the database DOMAIN CONSTRAINTS Information on CON
266. d is useful for development and debugging See the example in the SQL Invoked Routines chapter under Formal Parameters Example 3 1 User defined Session Variables DECLARE counter INTEGER DEFAULT 3 DECLARE result VARCHAR 20 DEFAULT NULL SET counter 15 CALL myroutine counter result Session Tables With necessary access privileges sessions can access all table including GLOBAL TEMPORARY tables that are defined in schemas Although GLOBAL TEMPORARY tables have a single name and definition which applies to all sessions that use them the contents of the tables are different for each session The contents are cleared either at the end of each transaction or when the session is closed Session tables are different because their definition is visible only within the session that defines a table The definition is dropped when the session is closed Session tables do not belong to schemas temporary table declaration DECLARE LOCAL TEMPORARY TABLE table name table element list ON COMMIT PRESERVE DELETE ROWS The syntax for declaration is based on the SQL Standard A session table cannot have FOREIGN KEY constraints but it can have PRIMARY KEY UNIQUE or CHECK constraints A session table definition cannot be modified by adding or removing columns indexes etc It is possible to refer to a session table using its name which takes precedence over a schema table of th
267. d HSQLDB Server Remember that the hostname in hsqls and https JDBC URLs must match the CN of the server certificate the port and instance alias that follows are not part of the certificate at all You only need to set truststore if the server cert is not approved by your system default truststore which a commercial certificate probably would be uds url jdbcrhsglodb hsglsi db admc com 9001 m2 username BLAINE password asecret truststore user home ca db db trust store Template for a Postgresql database urlid blainedb url jdbc postgresql idun africawork org blainedb username blaine password losungl driver org postgresql Driver Template for a MySQL database MySQL has poor JDBC support urlid mysql testdb url jdbc mysql hostname 3306 dbname username root password hiddenpwd driver com mysql jdbc Driver Note that databases in SQL Server and Sybase are traditionally used for the same purpose as schemas with more SQL compliant databases Template for a Microsoft SQL Server database using Microsoft s Driver I find that the JTDS driver is much more responsive than Microsoft s OLDER JDBC Driver urlid msprojsvr url jdbc microsoft sqlserver hostname DatabaseName DbName SelectMethod Cursor The SelectMethod setting is required to do more than one thing on a JDBC Session I guess Microsoft thought nobody would really use Java for anything other than a hello world program This is for Microsoft s SQL Server
268. d in the database 225 HyperSQL System Management The Java function should return an instance of org hsqldb jdbc JDBCArrayBasic constructed with a String argument that contains the role names Only a user with the DBA role can execute this statement SET DATABASE AUTHENTICATION FUNCTION EXTERNAL NAME CLASSPATH org anorg access AccessClass accessExernalMethod the Java method is defined like this public static java sql Array accessExternalMethod String database String user String password if externalCheck database user password return null throw new RuntimeException failed to authenticate 226 HyperSGL Chapter 12 Properties Fred Toussi The HSQL Development Group Revision 5039 Copyright 2002 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Connection URL The normal method of accessing a HyperSQL catalog is via the JOBC Connection interface An introduction to different methods of providing database services and accessing them can be found in the SQL Language chapter Details and examples of how to connect via JDBC are provided in our JavaDoc for JDBCConnection A uniform method is used to distinguish
269. d is NULL and the other is not NULL or if the elements are NOT equal then the result of the expression is TRUE If no comparison result is TRUE then the result of the predicate is FALSE The expression X IS NOT DISTINCT FROM Y is equivalent to NOT X IS DISTINCT FORM Y The following check returns true if startdate is not equal to enddate It also returns true if either startdate or enddate is NULL It returns false in other cases startdate IS DISTINCT FROM enddate Aggregate Functions aggregate function aggregate function aggregate function COUNT left paren asterisk right paren filter clause general set function filter clause array aggregate function filter clause general set function set function type left paren set quantifier value expression right paren set function type computational operation computational operation AVG MAX MIN SUM EVERY ANY SOME COUNT STDDEV POP STDDEV SAMP VAR SAMP VAR POP MEDIAN set quantifier DISTINCT ALL filter clause FILTER left paren WHERE search condition right paren array aggregate function ARRAY AGG GROUP CONCAT left paren set quantifier value expression order by clause SEPARATOR separator right paren lt separator gt character string literal
270. d open the script as a database with 2 0 Procedure 15 2 Upgrade Using the SCRIPT Procedure for Very Old Versions 1 Open the original database in the old version of DatabaseManager 2 Issue the SCRIPT command for example SCRIPT newversion script tocreate a script file containing a copy of the database 3 SHUTDOWN this database 4 Copy the original properties file into newversion properties in the same directory as newversion script 5 Try to open the new database newversion using DatabaseManager of version 1 8 1 6 Ifthere is any inconsistency in the data the script line number is reported on the console and the opening process is aborted Edit and correct any problems in the newversion script before attempting to open again Use 272 HyperSQL Deployment Guide the guidelines in the next section Manual Changes to the script File Use a programming editor that is capable of handling very large files and does not wrap long lines of text Manual Changes to the script File In HyperSQL 2 0 the full range of ALTER TABLE commands is available to change the data structures and their names However if an old database cannot be opened due to data inconsistencies or it uses index or column names that are not compatible with 2 0 manual editing of the script file can be performed and can be faster Version 2 0 does not accept duplicate names for indexes that were allowed before 1 7 2 Version 2 0 does not accept
271. d so on Values for the server database n property can use the mem file or res prefixes and connection properties as discussed under CONNECTIONS For example database O mem temp sql enforce strict size true Properties or default values specific to server properties are Table 13 2 server properties Value Default Description server port 9001 normal TCP IP port used for talking to clients All databases are or 554 if 1 served on the same port encrypted server no system exit true no System exit call when the database is closed Properties or default values specific to webserver properties are Table 13 3 webserver properties Value Default Description server port 80 normal or 443 TCP IP port used for talking to clients if TLS encrypted server default page the default web page for server server root En the location of served pages extension NO DEFAULT multiple entries such as html text html define the mime types of the static files served by the web server See the source for src org hsqldb server WebServer java fora list An example of the contents of a server properties file is given below server database 0 file opt db accounts server dbname 0 accounts server database 1 file opt db mydb server dbname l enrolments server database 2 mem adatabase server dbname 2 quickdb In the above example the server properties file indicates
272. d stored in memory In contrast the data for cached tables is not read into memory until the table is accessed Furthermore only part of the data for each CACHED table is held in memory allowing tables with more data than can be held in memory When the database is shutdown in the normal way all the data for MEMORY tables is written out to the disk In comparison the data in CACHED tables that has changed is written out during operation and at shutdown 198 HyperSGL System Management The size and capacity of the data cache for all the CACHED tables is configurable This makes it possible to allow all the data in CACHED tables to be cached in memory In this case speed of access is good but slightly slower than MEMORY tables For normal applications it is recommended that MEMORY tables are used for small amounts of data leaving CACHED tables for large data sets For special applications in which speed is paramount and a large amount of free memory is available MEMORY tables can be used for large tables as well You can change the type of the table with the SET TABLE lt table name TYPE CACHED MEMORY Jjstatement Large Objects HyperSQL 2 0 supports dedicated storage and access to BLOB and CLOB objects These objects can have huge sizes BLOB or CLOB is specified as the type of a column of the table Afterwards rows can be inserted into the table using a PreparedStatement for efficient transfer of large LOB
273. d value RETURN return statement lt return statement gt RETURN lt return value gt lt return value gt lt value expression gt NULL Return a value from an SQL function If the function is defined as RETURNS TABLE then the value is a TABLE expression such as RETURN TABLE SELECT otherwise the value expression can be any scalar expression In the examples below the same function is written with or without a BEGIN END block In both versions the RETURN value is a scalar expression CREATE FUNCTION an hour before max e type INT RETURNS TIMESTAMP RETURN SELECT MAX event time FROM atable WHERE event type e type 1 HOUR CREATE FUNCTION an hour before max e type INT RETURNS TIMESTAMP BEGIN ATOMIC DECLARE max event TIMESTAMP SET max event SELECT MAX event time FROM atable WHERE event type e type RETURN max event 1 HOUR END Control Statements In addition to the RETURN statement the following statements can be used in specific contexts ITERATE STATEMENT The ITERATE statement can be used to cause the next iteration of a labelled iterated statement a WHILE REPEAT or LOOP statement It is similar to the continue statement in C and Java iterate statement ITERATE statement label LEAVE STATEMENT 152 HyperSQL SQL Invoked Routines The LEAVE statement can be used to leave a labelled block When used in an iterated statement it is similar
274. data it is recommended not to change the same data using another ResultSet and not to execute SQL data change statements that modify the same data Sensitivity The sensitivity of the cursor relates to visibility of changes made to the data by the same transaction but without using the given cursor While the result set is open the same transaction may use statements such as INSERT or UPDATE and change the data of the tables from which the result set data is derived A cursor is SENSITIVE if it reflects those changes It is INSENSITIVE if it ignores such changes It is ASENSITIVE if behaviour is implementation dependent The SQL default is ASENSITIVE i e implantation dependent In HSQLDB all cursors are INSENSITIVE They do not reflect changes to the data made by other statements Holdability A cursor is holdable if the result set is not automatically closed when the current transaction is committed Holdability can be specified in the cursor declaration using the SQL qualifiers WITH HOLD or WITHOUT HOLD In JDBC holdability is specified using either of the following values for the Statement parameter HOLD CURSORS OVER COMMIT or CLOSE CURSORS AT COMMIT The SQL default is WITHOUT HOLD The JDBC default for HSQLDB result sets is WITH HOLD for read only result sets and WITHOUT HOLD for updatable result sets If the holdability of a ResultSet is specified in a conflicting manner in the SQL statement and the JDBC Statement object the
275. data to the database In mem catalogs CLOB and BLOB data is stored in memory In file catalogs this data is stored in a single separate file which has the extension lobs The size of this file can grow to huge terabyte figures By default a minimum 32 KB is allocated to each LOB You can reduced this if your LOBs are generally smaller LOB data should be store in the database using a JDBC PreparedStatement object The streaming methods send the LOB to the database in one operation as a binary or character stream Inside the database the disk space is allocated as needed and the data is saved as it is being received LOB data should be retrieved from the database using a JDBC ResultSet method When a streaming method is used to retrieve a LOB it is retrieved in large chunks in a transparent manner LOB data can also be retrieved as String or byte but these methods use more memory and may not be practical for large objects LOB data is not duplicated in the database when a lob is copied from one table to another The disk space is reused when a LOB is deleted and is no longer contained in any table This happens only at the time of a CHECKPOINT By using a dedicated LOB store HyperSQL achieves consistently high speeds usually over 20MB s for both storage and retrieval of LOBs There is an internal LOBS schema in the database to store the id s sizes and addresses of the LOBs but not the actual LOBS in a few system tables This schema i
276. ded when assigned to columns or variables of the given type The trailing spaces are still considered discardable for all character types Therefore if a string with trailing spaces is too long to assign to a column or variable of a given length the spaces beyond the type length are discarded and the assignment succeeds provided all the characters beyond the type length are spaces The VARCHAR and CLOB types have length limits but the strings are not padded by the system Note that if you use a large length for a VARCHAR or CLOB type no extra space is used in the database The space used for each stored item is proportional to its actual length If CHARACTER is used without specifying the length the length defaults to 1 For the CLOB type the length limit can be defined in units of kilobyte K 1024 megabyte M 1024 1024 or gigabyte G 1024 1024 1024 using the lt multiplier gt If CLOB is used without specifying the length the length defaults to 16M character string type CHARACTER CHAR left paren character length right paren CHARACTER VARYING CHAR VARYING VARCHAR left paren character length right paren LONGVARCHAR left paren character length right paren character large object type character large object type CHARACTER LARGE OBJECT CHAR LARGE OBJECT CLOB left paren character large object length
277. default warn lifecycle level doesn t give much feedback The task target validate docs is also very useful to DocBook builders The documentation license does not allow you to post modifications to our guides but you can modify them for internal use by your organization and you can use our DocBook system to write new DocBook documents related or unrelated to HyperSQL To create new DocBook documents create a subdirectory off of doc src for each new document with the main DocBook source file within having same name as the directory plus xm1 See the peer directory util guide or guide as an example If you use the high level tasks target gen docs or validate docs then copy and paste to add new stanzas to these targets in file build xml Editors of DocBook documents see previous paragraph for motive may find it useful to have a standalone XML validator so you can do your primary editing without involvement of the build system Use the Gradle target standaloneValidation for this It will tell you how to set a build property to tell it where to install the validator and will give instructions on how to use it 291 HyperSGL Building HyperSQL Jars There are several properties that can be used to dramatically decrease run times for partial doc builds Read about these properties in comment at the top of the file build docbook xml in the build directory validation skip html skip chunk skip fo skip e pdf skip
278. deterministic characteristic gt DETERMINISTIC NOT DETERMINISTIC SQL DATA access SQL DATA access characteristic The SOL data access indication clause indicates the extent to which a routine interacts with the database or the data stored in the database tables in different schemas SQL DATA NO SQL means no SQL command is issued in the routine body and can be used only for SQL JRT functions CONTAINS SQL means some SQL commands are used but they do not read or modify the SQL data READS SQL DATA and MODIFIES SQL DATA are self explanatory A CREATE PROCEDURE definition can use MODIFIES SQL DATA This is not allowed in CREATE FUNCTION Note that a PROCEDURE or a FUNCTION may have internal tables or return a table which are populated by the routine s statements These tables are not considered SQL DATA therefore there is no need to specify MODIFIES SQL DATA for such routines lt SQL data access indication gt NO SQL CONTAINS SQL READS SQL DATA MODIFIES SQL DATA NULL INPUT null call clause Null Arguments The null call clause is used only for functions If a function returns NULL when any of the calling arguments is null then by specifying RETURNS NULL ON NULL INPUT calls to the function are known to be redundant and do not take place when an argument is null This simplifies the coding of the SQL JRT Java methods and improves performance at the same time
279. did Gradle GUI Limitations The Gradle GUI is fairly new and lacks some of the power available to text based users Most significantly in my opinion is the following item for which I have opened Gradle issues 1855 There is no convenient way to set build properties If you want to change Ant or Gradle build settings edit the text file build properties inthe HyperSQL bui la directory creating it if it doesn t exist yet and enter your properties using Java properties file syntax You can also use 1ocal docbook properties in the same way for DocBook specific properties Building with Apache Ant You should use version 1 7 x of Ant Another Neat Tool to do Ant builds with HyperSQL Obtaining Ant Ant is a part of the Jakarta Apache Project e Home of the Apache Ant project http ant apache org e The Installing Ant http ant apache org manual install html installing page of the Ant Manual http ant apache org manual Follow the directions for your platform Building Hsqldb with Ant Once you have unpacked the zip package for hsqldb under the hsqldb folder in build there is a build xml file that builds the hsqldb jar with Ant Ant must be already installed To use it change to bui1d then type ant projecthelp This displays the available ant targets which you can supply as command line arguments to ant These include hsqldb to build the hsqldb jar file explainjars Lists all targets w
280. dk 262 HyperSGL HyperSQL on UNIX By default MainInvoker will just run TARGET CLASS with no args Example that runs just the TARGET CLASS with the specified arguments INVOC_ADDL_ARGS silent false but use server properties property instead Example that runs the TARGET CLASS plus a WebServer fINVOC ADDL ARGS org hsqldb server WebServer Note the empty string preceding the class name Example that starts TARGET CLASS with an argument a WebServer your own application with its args i e the HSQLDB Servers are embedded in your application Set SERVER ADDL CLASSPATH too INVOC_ADDL_ARGS silent false org hsqldb server WebServer com acme Stone env prod localhost but use server properties for silent option instead Example to run a non TLS server in same JVM with a TLS server In this case TARGET CLASS is Server which will run both in TLS mode by virtue of setting the tls keyStore and keyStorePassword settings in server properties as described below plus an additional Server with overridden tls and port settings INVOC ADDL ARGS org hsqldb server Server port 9002 tls false This is an important use case If you run more than one Server instance you can specify different parameters for each here even though only one server properties file is supported Note that you use nested quotes to group argum
281. doc name doc target See the file doc src readme docauthors txt for details about our DocBook build system though as I write this it is somewhat out of date 292 HyperSQL Appendix C HyperSQL with OpenOffice How to use HyperSQL with OpenOffice org Fred Toussi The HSQL Development Group Revision 5051 2012 08 06 00 12 50 0100 HyperSQL with OpenOffice OpenOffice org LibreOffice ApacheOpenOffice includes HyperSQL and uses it for embedded databases Our collaboration with OpenOffice org developers over the last few years has benefited the development and maturity of HyperSQL Before integration into OOo HSQLDB was intended solely for application specific database access The application developer was expected to resolve any integration issues Because OpenOffice org is used by a vast range of users from schoolchildren to corporate developers a much higher level of quality assurance has been required We have achieved it with constant help and feedback from OOo users and developers Apart from embedded use you may want to use OpenOffice LibreOffice with a HyperSQL server instance The typical use for this is to allow multiple office users access to the same database There is also a strong case for using OpenOffice to develop your database schema and application even if the database is intended for your own application rather than OpenOffice HSQLDB version 1 8 0 is included in OOo ApacheOpenOffice and LibreOffi
282. ds of Java classes that can be used for routines based on Java static methods See the SQL Invoked Routines chapter 242 HyperSQL Chapter 13 HyperSQL Network Listeners Servers Server WebServer and Servlet Fred Toussi The HSQL Development Group Revision 4903 Copyright 2002 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Listeners As describedin the Running and Using HyperSQL chapter network listeners servers provide connectivity to catalogs from different JVM processes The HyperSQL listeners support both ipv4 and ipv6 network addressing HyperSQL Server This is the preferred way of running a database server and the fastest one This mode uses the proprietary hsql communications protocol The following example of the command for starting the server starts the server with one default database with files named mydb and the public name alias of xdb java cp lib hsqldb jar org hsqldb server Server database 0 file mydb dbname 0 xdb Alternatively a server properties file can be used for passing the arguments to the server This file must be located in the directory where the command is issued java cp lib hsqld
283. dure statements In BEFORE triggers you can include SET statements to modify the inserted or updated rows In AFTER triggers you can include INSERT DELETE and UPDATE statements to change the data in other database tables SELECT and CALL statements are allowed in BEFORE and AFTER triggers CALL statements in BEFORE triggers should not modify data The third form specifies a call to a Java method Two examples of a trigger with a block are given below The block can include elements discussed in the SQL Invoked Routines chapter including local variables loops and conditionals You can also raise an exception in such blocks in order to terminate the execution of the SQL statement that caused the trigger to execute the trigger throws an exception if a customer with the given last name already exists CREATE TRIGGER trigone BEFORE INSERT ON customer REFERENCING NEW ROW AS newrow FOR EACH ROW WHEN newrow id 100 BEGIN ATOMIC IF EXISTS SELECT FROM CUSTOMER WHERE CUSTOMER LASTNAME NEW LASTNAME THEN SIGNAL SQLSTATE 45000 SET MESSAGE TEXT already exists END IF END for each row inserted into the target the trigger insert a row into the table used for logging CREATE TRIGGER trig AFTER INSERT ON testtrig BEFORE othertrigger REFERENCING NEW ROW AS newrow FOR EACH ROW WHEN newrow id 1 BEGIN ATOMIC INSERT INTO triglog VALUES newrow id newrow data inserted more statements can be included END
284. e tar or tar gz file to be created in your file system and dbdir dbname is the file path to the catalog file base name in same fashion as in server database settings and JDBC URLs with catalog type file Examining Backups You can list the contents of backup tar files with DbBackup on your operating system command line or with any Pax compliant tar or pax client this includes GNU tar 201 HyperSGL System Management Example 11 3 Listing a Backup with DbBackup java cp hsqldb jar org hseqidb lib tar DbBackup list tardir backup tar You can also give regular expressions at the end of the command line if you are only interested in some of the file entries in the backup Note that these are real regular expressions not shell globbing patterns so you would use script to match entries ending in script not script You can examine the contents of the backup in their entirety by restoring the backup as explained in the following section to a temporary directory Restoring a Backup You use DbBackup on your operating system command line to restore a catalog from a backup Example 11 4 Restoring a Backup with DbBackup java cp hsqldb jar org hsqldb lib tar DbBackup extract tardir backup tar dbdir where tardir backup tar is a file path to the tar or tar gz file to be read and dbdir is the target directory to extract the catalog files into Note that dbdir specifies a directory path
285. e SET FILES LOB SCALE set files lob scale set files lob scale statement SET FILES LOB SCALE scale value Changes the scale factor for the lobs file The scale is interpreted in kilobytes The default scale is 32 and allows 64TB of lob data storage capacity The scale can be reduced in order to improve storage efficiency If the lobs are a lot smaller than 32 kilobytes reducing the scale will reduce wasted space The scale values 1 2 4 8 16 32 are allowed For example if the average size of lobs is 4 kilobytes the default scale of 32 will result in 28KB wasted space for each lob Reducing the lob scale to 2 will result in average 1KB wasted space for each lob This command can be used only when there is no lob in the database Only a user with the DBA role can execute this statement This is equivalent to the connection property hsgldb lob file scale SET FILES SCRIPT FORMAT set files script format set files script format statement SET FILES SCRIPT FORMAT TEXT COMPRESSED Changes the compression setting for database scripts The default is text Using COMPRESSED results in the storage of the script file in gzip compressed form Using this command causes a CHECKPOINT Only a user with the DBA role can execute this statement SET TABLE TYPE set table type set table type statement SET TABLE table name TYPE MEMORY CACHED Changes th
286. e This depends on the types of objects in database rows for example with binary objects the factor is less than 2 with character strings the factor is just over 2 and with date and timestamp objects the factor is over 3 The value can range between 100 KB 4 GB The default is 10 000 representing 10 000 kilobytes If the value is set via SET FILES then it becomes effective after the next database SHUTDOWN or CHECKPOINT SET FILES CACHE SIZE numeric value Table 12 43 Size Scale of Disk Table Storage Name Default Description hsqldb cache_file_scale unit used for storage of rows in the data file The default value corresponds to a maximum size of 64 GB for the data file This can be increased to 64 128 256 512 or 1024 resulting in up to 2 TB GB storage Settings below 32 in older databases are preserved until a SHUTDOWN COMPACT SET FILES SCALE lt numeric value gt Table 12 44 Size Scale of LOB Storage Name Description hsqldb lob file scale unit used for storage of lobs in the lobs file The default value represents units of 32KB When the average size of individual lobs in the database is smaller a smaller unit can be used to reduce the overall size of the lobs file Values 1 2 4 8 16 32 can be used SET FILES LOB SCALE lt numeric value gt Table 12 45 Internal Backup of Database Files Name Default Description hsqldb inc_backup i
287. e When switching from another SQL dialect the following should be considered Numeric types TINYINT SMALLINT INTEGER and BIGINT are types with fixed binary precision These types are more efficient to store and retrieve NUMERIC and DECIMAL are types with user defined decimal precision They can be used with zero scale to store very large integers or with a non zero scale to store decimal fractions The DOUBLE type is a 64 bit approximate floating point types HyperSQL even allows you to store infinity in this type The BOOLEAN type is for logical values and can hold TRUE FALSE or UNKNOWN Although HyperSQL allows you to use one and zero in assignment or comparison you should use the standard values for this type Character string types are CHAR L VARCHAR L and CLOB CHAR is for fixed width strings and any string that is assigned to this type is padded with spaces at the end Do not use this type for general storage of strings If you use CHAR without the length L then it is interpreted as a single character string Use VARCHAR L for general strings There are only memory limits and performance implications for the maximum length of VARCHAR L If the strings are larger than a few kilobytes consider using CLOB The CLOB types is for very large strings Do not use this type for short strings as there are performance implications The CLOB type is a better choice for the storage of long strings By default LONGVARCHAR is a synonym for a lo
288. e lt num value expr gt Elements are discarded from the end of the array Foundation SEQUENCE_ARRAY SEQUENCE_ARRAY lt value expr 1 gt lt value expr 2 gt lt value expr 3 Returns a new array that contains a sequence of values The lt value expr 1 gt is the lower bound of the range The lt value expr 2 gt is the upper bound of the range The lt value expr 3 gt is the increment The elments of the array are within the inclusive range The first element is lt value expr 1 gt and each subsequent element is the sum of the previous element and the increment If the increment is zero only the first element is returned When the increment is negative the lower bound should be larger than the upper bound The type of the arguments can be all number types or a datetime range and an interval for the third argument HyperSQL In the examples below a number sequence and a date sequence are shown The UNNEST table expression is used to form a table from the array SEQUENCE ARRAY 0 100 5 ARRAY OTO Ooo A0 A0 poy OU ROO O5 SESS SELECT FROM UNNEST SEQUENCE_ARRAY 10 12 1 Ci 10 al 12 SELECT FROM UNNEST SEQUENCE ARRAY CURRENT DATE CURRENT DATE 6 DAY 1 DAY WITH ORDINALITY AS T D T 2010 08 01 2010 08 02 2010 08 03 2010 08 04 2010 08 05 2010 08 06 2010 08 07 JOU NnroON kr General Functions General functions can take different types of arguments Some General Functions accept a
289. e of most parts of the database engine This documentation covers the latest HyperSQL version 2 2 This documentation is regularly improved and updated The latest updated version can be found at http hsqldb org doc 2 0 If you notice any mistakes in this document or if you have problems with the procedures themselves please use the HSQLDB support facilities which are listed at http hsqldb org support Available formats for this document This document is available in several formats You may be reading this document right now at http hsqldb org doc 2 0 or in a distribution somewhere else I hereby call the document distribution from which you are reading this your current distro http hsqldb org doc 2 0 hosts the latest production versions of all available formats If you want a different format of the same version of the document you are reading now then you should try your current distro If you want the latest production version you should try http hsqldb org doc 2 0 Sometimes distributions other than http hsqldb org doc 2 0 do not host all available formats So if you can t access the format that you want in your current distro you have no choice but to use the newest production version at http hsqldb org doc 2 0 Table 1 Available formats of this document format your distro at http hsqldb org doc 2 0 Chunked HTML http hsqldb org doc 2 0 guide All in one HTML guide html http hsqldb org doc 2 0 g
290. e I have so far failed to get that to succeed Classifiers in in ivy xml are supported if using Gradle as covered below Example 15 10 Sample Range Maven Dependency See note above about Maven range specifications lt dependency gt lt dependency gt groupId org hsqldb groupId sartifactid hsgldbsartifactie version 2 version 1 Scope defaults to compile lt scope gt test lt scope gt Use a classifier to pull one of our alternative jars lt classifier gt jdk5 lt classifier gt gt Example 15 11 Sample Range Gradle Dependency jdk5 dependencies compile group org hsqldb name hsqldb version 2 he GAS A fia e a dependencies runtime org hsqldb hsqldb 2 jadk6debugGjar org hsqldb sqltool 2 jdk6debug jar If you want to use an ivy xml file with a Gradle build you will need use the Ivyxml Gradle Plugin https github com unsaved gradle ivyxml plugin It just takes a few links of code in your build gradle file to hook in ivyxml See the Ivyxml documentation https github com unsaved gradle ivyxml plugin raw master README txt to see exactly how Example 15 12 Sample Range ivy xml loaded by Ivyxml plugin 277 H ype rSQL Deployment Guide ivy module version 2 0 xmlns m http ant apache org ivy maven gt dependency org org hsqldb name hsqldb rev 2 m classifier jdk5 Example 15 13 Sample Range Gro
291. e additional pairs of lt value expr match n and lt value expr result n gt comparison is repeated until a match is found the result is returned If no match is found the lt value expr default is returned if it is specified otherwise NULL is returned The type of the return value is a combination of the types of the lt value expr result gt arguments HyperSQL GREATEST GREATEST lt value expr 1 gt lt value expr gt The GREATEST function takes one or more arguments It compares the arguments with each other and returns the greatest argument The return type is the combined type of the arguments Arguments can be of any type so long as they are comparable HyperSQL IFNULL ISNULL 192 HyperSQL Built In Functions IFNULL ISNULL lt value expr 1 gt lt value expr 2 Returns lt value expr 1 gt if it is not null otherwise returns lt value expr 2 The type of the return value is the type of lt value expr 1 gt Almost equivalent to SQL Standard COALESCE lt value expr 1 gt lt value expr 2 gt function but without type modification JDBC LEAST LEAST lt value expr 1 gt lt value expr gt The LEAST function takes one or more arguments It compares the arguments with each other and returns the smallest argument The return type is the combined type of the arguments Arguments can be of any type so long as they are comparable HyperSQL LO
292. e classpath probably in a Jar A Java resource is stored in a compressed format and is decompressed in memory when it is used For this reason a res database should not contain large amounts of data and is always read only Connection c DriverManager getConnection jdbc hsqldb res org my path resdb SA The first time in process connection is made to a database some general data structures are initialised and a few helper threads are started After this creation of connections and calls to JDBC methods of the connections execute as if they are part of the Java application that is making the calls When the SOL command SHUTDOWN is executed the global structures and helper threads for the database are destroyed Note that only one Java process at a time can make in process connections to a given file database However if the file database has been made read only or if connections are made to a res database then it is possible to make in process connections from multiple Java processes Server Modes For most applications in process access is faster as the data is not converted and sent over the network The main drawback is that it is not possible by default to connect to the database from outside your application As a result you cannot check the contents of the database with external tools such as Database Manager while your application is running HyperSGL Running and Using HyperSQL Server modes prov
293. e en Pe e pike Ev te Ge pr dips e PURUS Pr kan 244 Starting a Server from your Application sesssesseeeee eee e mene Henne hen nennen 246 Allowing a Connection to Open or Create a Database ssssssessese me 246 Specifying Database Properties at Server Start sess eee 246 Ju Mica M Vm 247 eniin de rU 247 Encrypting your JDBC connection siccis ienien ensia etae tek pe enn etae en s vav ea de dd ena 247 JSSE uat ee ide ant Dace rm ee voye dIo seein voten OE Ge e E IER ODD UM UE CEPR cede 249 Making a Private key Keystore 1 eco retener reete tk bosni yon eene a reveren ter cose us eee EE et ae rv Res 249 Automatic Server or WebServer startup on UNIX sessssss eme 250 Network Access COMO 14 deese decseseteg sees abitan kaki esae br dy guider i pede gete miyo dundee eto ee erewds 250 14 Hyper SOL on UNIX 2 3 kode sak sri PEDE RU sis Gab cx Voss RE Uber b Ze DA oL eoa e uo ese ee De ute eee 252 luno c 252 TASTAN AMON MC EET 252 Setting up Database Catalog and Listener esses HH eere 254 Accessing your Database 5 2 ci rr eed vi ena UH En LU e gai du EY SY bese E Yo Une Leben vo Ve kan ke ken 255 Create additional ACCOUNUS 1 5 iso eres torte ro si kou rale iben ede boko sep eese EE t de E ted ERE T SERES HEEL DS i 259 SHUJO WA ua it sos ba cies i ets bated Semel ae doen ux des cob e discute A s ois ok c al san bande seed ais pa a lis a dees 259 Running Hsqldb as a System Daemon
294. e end of the tests You may actually want to use a file database or a server instance that serves a file database in preference to a mem database As HyperSQL logs the DDL and DML statements in the log file this file can be used to check what is being sent to the database Note that UPDATE statements are represented by a DELETE followed by an INSERT statement Statements are written out when the connection commits The write delay also has an effect on how soon the statements are written out By default the write delay is 0 5 second The new SQL logging feature in version 2 2 x and later records all executed statements and can be used for debugging your application Some types of tests start with a database that already contains the tables and data and perform various operations on it during the tests You can create and populate the initial database then set the property files readonly true in 269 HyperSQL Deployment Guide the properties file of the database The tests can then modify the database but these modifications are not persisted after the tests have completed Databases with files readonly true can be placed within the classpath and in a jar file In this case the connection URL must use the res protocol which treats the database as a resource Embedded Databases in Desktop Applications In this usage the amount of data change is often limited and there is often a requirement to persist the data immediate
295. e etas eu sauer kle EEEE m ke ol tueur Du ber REN 237 1241 Rows Cached In Memory 511i err eee peto sete PE Repo e ni EN pie ta kan RR NR ES Re EE CHER ke 237 12 42 Size of Rows Cached in MEMOLY baseeeLeeerei tret ipee on kis aan these a EREE KEKEE nanan n ekinn 237 12 43 Size Scale of Disk Table Storage 0sccenseeenoeecnoeseeteeepoeecnetetspeneecnersssntnsebecssberssanensoeses 238 12 44 Size Scale OF LOB Storage aice hsssdsessaiecwedwnndecs teense EEEE SKEE EEEE secco dp rote ve ETE t k be veb pie kalm ne 238 12 45 Internal Backup of Database Files 11 etr ertet nma ep ens ouaceessoneeepeaonckyeseseNteeaseneds 238 12 46 UsS6 01 Lock FNE dp 238 12 47 Logging Data Change Statements 12 ettet ok dezod all ie ao il ble a la a ke ma kabap b 239 12 48 Automatic Checkpoint Frequency v sc ccciccsecstece roi noon sese oasv endende note basin ande konin rea bank e en be kwe ane n kwen eaten 239 12 49 Automatic Defrag at Checkpoint 4 i seen babe e tree tte Ewop e ka e REL pep Be e ok ERR ERG 239 HyperSGL HyperSQL User Guide 12 50 Logging Data Change Statements Frequency sss e eere 239 12 51 Logging Data Change Statements Frequency sss emere 239 12 52 Use of NIO for Disk Table Storage ssesseeee e heme mH e hee hene eere 240 12 53 Use of NIO for Disk Table Storage ssesseee I Hem HII hee hene hene 240 12 54 Rec
296. e in process deployments especially with older JVM implementations Only a user with the DBA role can execute this statement SET DATABASE UNIQUE NAME set database unique name set database unique name statement SET DATABASE UNIQUE NAME identifier I Each HyperSQL catalog database has an engine generated internal name This name is a 16 character long string beginning with HSQLDB and based on the time of creation of the database The name is used for the log events that are sent to external logging frameworks The new name must be exactly 16 characters long with no spaces Only a user with the DBA role can execute this statement SET DATABASE TRANSACTION CONTROL set database transaction control statement set database transaction control statement SET DATABASE TRANSACTION CONTROL LOCKS MVLOCKS MVCC Set the concurrency control system for the database It can be issued only when all sessions have been committed or rolled back This command and its modes is discussed in the Sessions and Transactions chapter Only a user with the DBA role can execute this statement This is equivalent to the connection property hsqldb tx SET DATABASE TRANSACTION ROLLBACK ON CONFLICT set database transaction rollback on conflict statement Lu set database transaction rollback on conflict statement SET DATABASI TRANSACTION ROLLBACK ON CONFLICT TRUE FALSE When a trans
297. e new id Iterated Statements Various iterated statements can be used in routines In these statements the SOL statement list consists of one or more SQL statements The search condition can be any valid SQL expression of BOOLEAN type LOOP loop statement loop statement beginning label colon LOOP SQL statement list END LOOP ending label WHILE while statement while statement beginning label colon WHILE search condition DO SOL statement list END WHILE ending label REPEAT repeat statement repeat statement beginning label colon REPEAT SQL statement list UNTIL search condition END REPEAT ending label 149 HyperSQL SQL Invoked Routines In the example below a multiple rows are inserted into a table in a WHILE loop loop label WHILE my var gt 0 DO INSERT INTO CUSTOMERS VALUES DEFAULT my var SET my var my var 1 IF my var 10 THEN SET my var 8 END IF IF my var 22 THEN LEAVE loop label END IF END WHILE loop label Iterated FOR Statement The for statement is similar to other iterated statement but it is always used with a cursor declaration to iterate over the rows of the result set of the cursor and perform operations using the values of each row FOR for statement for statement beginning label colon FOR
298. e or Containing Dollar Characters sss 231 12 12 Reference to Columns Names s n ase ew ao twe law iere pd kwi ee be Luce kt mw Petre ce pns uu ee peer ol iode ue pk seca buie 231 LPS cupida Mm 231 12 14 Type Enforcement in Comparison and Assignment sssseseeee IH Hehe 231 12 15 Foreign Key Triggered Data Change ssssss Hem emere hen hene 232 12 16 Use of LOB for LONGV AR Types iii iii ie ri v ti ace shad reto Dese rece be sp torn kwe law k asa med kalen be kak e 232 12 17 Concatenation with NU LL kise ese rete pepe eet rera peret reet E poin ego EEE EEEE EE 232 12 18 NULL in Multi Column UNIQUE Constraints l tete tett aaa ea ae eaeaaoeaoaeaeatasensonoesoeoooosoesoooeoone 232 12 19 Truncation or Rounding in Type Conversion cece cece ceee cece tea tenneenooatooaeooneoonsoonsoonsoonooonoe 233 12 20 Decimal Scale of Division and AVG Values Hee Hehe hhenenree 233 12 21 Support for NAN Values 12e terre rete en e Rr eR epo sacs e ER lp ll FREUE rM Rer bd A Ek a 233 12 22 Sort order f NULL Values 15 eiii kata sok vice aede bles oki aw seek m o REDE sed KRE eu EEIE a DR koka EEEE RES 233 12 23 String comparison with padding eee cece cece eee ce ence ence Hm eme m enm entren entren 233 12 24 DB2 Style P dM 234 12 25 MSSQL Style Syntax iiie et better eee YR IE c A ER pex Red l RE OPRERVRU Res RAN e o Edu EU e RE 234 12
299. e same name To distinguish a session table from schema tables the pseudo schema names MODULE or SESSION can be used An example is given below Example 3 2 User defined Temporary Session Tables DECLARE LOCAL TEMPORARY TABLE buffer id INTEGER PRIMARY KEY textdata VARCHAR 100 ON COMMIT PRESERVE ROWS INSERT INTO module buffer SELECT id firstname lastname FROM customers do some more work DROP TABLE module buffer or use alternative pseudo schema name DROP TABLE session buffer 31 HyperSGL Sessions and Transactions Session tables can be created inside a transaction Automatic indexes are created and used on session tables when necessary for a query or other statement By default session table data is held in memory This can be changed with the SET SESSION RESULT MEMORY ROWS statement Transactions and Concurrency Control HyperSQL 2 0 has been fully redesigned to support different transaction isolation models It no longer supports the old 1 8 x model with dirty read Although it is perfectly possible to add an implementation of the transaction manager that supports the legacy model we thought this is no longer necessary The new system allows you to select the transaction isolation model while the engine is running It also allows you to choose different isolation levels for different simultaneous sessions HyperSQL 2 0 supports three concurrency control models two phase l
300. e section under SQL PSM routines Returning Data From Procedures on how to use the JDBC CallableStatement interface to call the procedure and to get the OUT and INOUT arguments and to use the ResultSet objects returned by the procedure Java Static Methods The static methods that are used for procedures and functions must be declared in a public class The methods must be declared as public static For functions the method return type must be one of the JDBC supported types The IN parameters of the method must be declared as one of the supported types The OUT and INOUT parameters must be declared as Java arrays of supported types If the SQL definition of a function includes RETURNS NULL ON NULL INPUT then the IN parameters of the Java static function can be int or long primitives otherwise they must be Integer or Long The declared Java arrays for OUT and INOUT parameters for SQL INTEGER or BIGINT must be Integer or Long respectively If the SQL definition of the routine includes NO SQL then no JDBC method call is allowed to execute in the method body Otherwise a JDBC Connection can be used within the Java method to access the database If the definition includes CONTAINS SQL then no table data can be read If the definition includes READS SQL DATA then no table data can be modified If the definition includes MODIFIES SQL DATA then data can be modified In all modes it is not allowed to execute DDL statements that change the schema def
301. e seed doo ra ea POR SE 167 Trigger Acton In Java 00 week boss ao eisaskaviceovecy dana Poena ett E ke E eis ua eec ed eee Loeb bet oes 168 Juden 169 10 Built In TCI r 172 vi HyperSQL HyperSQL User Guide OVGEVIGW pies akyisase ote sese an yes ese diobe dwe eko ra E kasiet aste da ine E degssus Ou pe be dugeiiassweaieeewseder 172 String and Binary String Functions 20 000 cece ee ee eee cece cece cena ee ae oo m eme e ene en he mre rennen 173 N meric PUNCHIONS iscciusssussanesnrereusesabadnesumenss ty bu kiye a E suet otneaevenss E E E E EE EET 178 Date Time and Interval Functions l lllllllllllllleoe tot to aa ane aa cena ote one mH HI men men emer meer eren 182 Functions to Report the Time Zone 0 0 0 0 cece cee eee ce eme emeret hene 182 Functions to Report the Current Datetime e emm enhn 183 Functions to Extract an Element of a Datetime sss Hee 184 Functions for Datetime Arithmetic esses ehem hem memet hene 186 Functions to Convert or Format a Datetime sess Her 188 Array FUNCHUONS E cp mm 190 General Functions M 191 System dud EE 193 11 System Management Rr 198 Mode of Operation and Tables sss ee mee hene hen hee hee en hen enne nne 198 Mode OF Operation M M 198 ADIOS EE 198 Large ODJEC S EE 199
302. e shared locks it will go ahead If either of the locks is an exclusive lock the engine will put the session in wait until the other session commits or rolls back its transaction In some cases the engine will invalidate the transaction of the current session if the action would result in deadlock HyperSQL also supports explicit locking of a group of tables for the duration of the current transaction Use of this command blocks access to the locked tables by other sessions and ensures the current session can complete the intended reads and writes on the locked tables If a table is read only it will not be locked by any transaction The READ UNCOMMITTED isolation level can be used in 2PL modes for read only operations It is the same as READ COMMITTED plus read only The READ COMMITTED isolation level is the default It keeps write locks on tables until commit but releases the read locks after each operation The REPEATABLE READ level is upgraded to SERIALIZABLE These levels keep both read and write locks on tables until commit It is possible to perform some critical operations at the SERIALIZABLE level while the rest of the operations are performed at the READ COMMITTED level Note two phase locking refers to two periods in the life of a transaction In the first period locks are acquired in the second period locks are released No new lock is acquired after releasing a lock 32 HyperSGL Sessions and Transactions Two
303. e storage type of an existing table between CACHED and MEMORY types Only a user with the DBA role can execute this statement Authentication Settings Two settings are available for authentication control When the default password authentication is used the passwords can be checked for complexity according to administrative rules SET DATABASE PASSWORD CHECK FUNCTION 224 HyperSGL System Management set database password check function set database password check function statement SET DATABASE PASSWORD CH FUNCTION routine body NONE Ij Q A The routine body is the body of a function that has a VARCHAR parameter and returns a BOOLEAN This function checks the PASSWORD submitted as parameter and returns TRUE if it conforms to complexity checks or FALSE if it does not The lt routine body gt can be an SQL block or an external Java function reference This is covered in the SQL Invoked Routines chapter To disable this mechanism the token NONE can be specified instead of the lt routine body gt Only a user with the DBA role can execute this statement In the examples below an SQL function and a Java function are used SET DATABASE PASSWORD CHECK FUNCTION BEGIN ATOMIC IF CHAR_LENGTH PASSWORD gt 6 THEN RETURN TRUE ELSE RETURN FALSE END IF END SET DATABASE PASSWORD CHECK FUNCTION EXTERNAL NAME CLASSPATH org anorg access AccessClass accessMethod the Java m
304. e sure that the bin directory under your Ant home is in your search path Run the following command ant hsqldb This will build a new HSQLDB HOME 1ib hsqldb jar See the Building HyperSQL Jars appendix if you want to build anything other than hsqldb jar with all default settings Setting up a HyperSQL Persistent Database Catalog and a HyperSQL Network Listener If you installed from an OS specific package you may already have a catalog and listener pre configured See if your package includes a file named server properties make use of your packaging utilities If you do then I suggest that you still read this section while you poke around in order to understand your setup 1 Selecta UNIX user to run the database process JVM as If this database is for the use of multiple users or is a production system or to emulate a production system you should dedicate a UNIX user for this purpose In my 254 HyperSGL HyperS QL on UNIX examples I use the user name hsqldb In this chapter I refer to this user as the HSQLDB OWN user will own the database catalog files and the JVM processes If the account doesn t exist then create it On all system 5 UNIXes and most hybrids including Li run as root something like ER since that nux you can useradd c HSQLDB Database Owner s bin bash m hsqldb BSD variant users can use a similar pw useradd hsqldb command 2 Become the HS
305. e version is discussed in the next section JDBC SIGN SIGN num value expr gt Returns an INTEGER indicating the sign of the argument If the argument is negative then 1 is returned If it is equal to zero then O is returned If the argument is positive then 1 is returned JDBC SIN SIN num value expr gt Returns the sine of the argument an angle expressed in radians as a value of DOUBLE type JDBC SQRT SORT num value expr gt Returns the square root of the argument as a value of DOUBLE type JDBC and Foundation TAN TAN num value expr gt Returns the tangent of the argument an angle expressed in radians as a value of DOUBLE type JDBC TO NUMBER TO NUMBER char value expr gt Performs a cast from character to DECIMAL number The character string must consist of digits and can have a decimal point Use the SQL Standard CAST expression instead of this non standard function HyperSQL TRUNC TRUNC num value expr gt int value expr gt This is a similar to the TRUNCATE function when the first argument is numeric If the second argument is omitted Zero is used in its place The datetime version is discussed in the next section HyperSQL TRUNCATE TRUNCATE num value expr gt int value expr gt 181 Built In Functions HyperSQL Returns a value in the same type as num value expr but may reduce the scale of DECIMAL and NUMERIC values
306. e versions of HyperSQL you will want to retain the version number in the directory tree somehow cd ancestor of new hsqldb home unzip path to file zip All the files in the zip archive will be extracted to underneath a new subdirectory named like hsqldb 2 0 2a hsqldb Take a look at the files you installed Under hsqldb for zip file installations Otherwise use the utilities for your packaging system The most important file of the HyperSQL system is hsqldb jar which resides in the subdirectory lib Depending on who built your distribution your file name may have a version label in it like hsgldb 1 2 3 4 jar Important For the purposes of this chapter I define HSQLDB HOME to be the parent directory of the lib directory that contains hsqldb jar E g if your path to hsqldb jar is a b hsqldb lib hsqldb jar then your HSQLDB HOME is a b hsqldb Furthermore unless I state otherwise all local file paths that I give are relative to the HSOLDB_HOME If the description of your distribution says that the hsqldb jar file will work for your Java version then you are finished with installation Otherwise you need to build a new hsqldb jar file 253 HyperSGL HyperSQL on UNIX If you followed the instructions above and you still don t know what Java version your hsqldb jar supports then try reading documentation files like readme txt README TXT INSTALL txt etc As I said above our n
307. e with assertions Assertions An ASSERTION is a top level schema objects It consists of a lt search condition gt that must not be false can be unknown Assertions share a name space with constraints Triggers A TRIGGER is a child schema object that always belongs to a TABLE or a VIEW Each time a DELETE UPDATE or INSERT is performed on the table or view additional actions are taken by the triggers that have been declared on the table or view Triggers are discussed in detail in Triggers chapter 48 HyperSGL Schemas and Database Objects Routines Routines are user defined functions or procedures The names and usage of functions and procedures are different FUNCTION is a routine that can be referenced in many types of statements PROCEDURE is a routine that can be referenced only in a CALL statement There is a separate name space for routines Because of the possibility of overloading each routine can have more than one name The name of the routine is the same for all overloaded variants but each variant has a specific name different from all other routine names and specific names in the schema The specific name can be specified in the routine definition statement Otherwise it is assigned by the engine The specific name is used only for schema manipulation statements which need to reference a specific variant of the routine For example if a routine has two signatures each signature has its own specific name
308. eases snapshots lt enabled gt true lt enabled gt lt updatePolicy gt always lt updatePolicy gt lt checksumPolicy gt fail lt checksumPolicy gt lt snapshots gt lt id gt hsqldb_snapshots lt id gt lt name gt HyperSQL Snapshots lt name gt lt url gt http hsqldb org repos lt url gt lt layout gt default lt layout gt lt repository gt Snapshot Dependency Specification Examples Example 15 4 Sample Snapshot Ivy Dependency dependency org org hsqldb name hsqldb rev SNAPSHOT conf buildOnly gt Example 15 5 Sample Snapshot Maven Dependency lt dependency gt groupId org hsqldb groupId corntuifactLidshsgidbsaneitactrcd lt version gt SNAPSHOT lt version gt Scope defaults to compile lt scope gt test lt scope gt gt lt dependency gt Example 15 6 Sample Snapshot Gradle Dependency dependencies compile group org hsqldb name hsqldb version SNAPSHOT dependencies runtime org hsqldb hsqldb SNAPSHOT org hsqldb sqltool SNAPSHOT If you want to use an ivy xml file with a Gradle build you will need use the Ivyxml Gradle Plugin https github com unsaved gradle ivyxml plugin It just takes a few links of code in your build gradle file to hook in ivyxml See the Ivyxml documentation https github com unsaved gradle ivyxml plugin raw master README txt to see exactly how Example 15 7 Sample Snapshot ivy xml loaded by Ivyxml plug
309. ebServer instead of a Server then make sure you have a healthy WebServer with a webserver properties set up adjust your URLs in sqltool rc and set TARGET CLASS in the config file By following the commented examples in the config file you can start up any number of Server and or WebServer listener instances with or without TLS encryption and each listener instance can serve any number of HyperSQL catalogs independent data sets all with optimal efficiency from a single JVM process There are instructions in the init script itself about how to run multiple independently configured JVM processes Most UNIX installations however will run a single JVM with a single Listener instance which serves multiple catalogs for easier management and more efficient resource usage After you have the init script set up root can use it anytime to start or stop HSQLDB Le not just at system bootup or shutdown Portability of hsqldb init script The primary design criterion of the init script is portability It does not print pretty color startup shutdown messages as is common in late model Linuxes and HPUX and it does not keep subsystem state files or use the startup shutdown functions supplied by many UNIXes because these features are all non portable Offsetting these limitations this one script does it s intended job great on the UNIX varieties I have tested and can easily be modified to accommodate other UNIXes While you don t have tight integra
310. ed in the view after the change If WITH CASCADED CHECK OPTION is specified then if the query expression ofthe view references another view then the search condition of the underlying view should also be satisfied by the update or insert operation DROP VIEW drop view statement drop view statement DROP VIEW IF EXISTS table name IF EXISTS drop behavior Destroy a view The drop behavior is similar to dropping a table ALTER VIEW alter view statement alter view statement ALTER VIEW table name view specification AS query expression WITH CASCADED LOCAL CHECK OPTION Alter a view The statement is otherwise identical to CREATE VIEW The new definition replaces the old If there are database objects such as routines or views that reference the view then these objects are recompiled with the new view definition If the new definition is not compatible the statement fails Domain Creation and Manipulation CREATE DOMAIN domain definition domain definition CREATE DOMAIN domain name AS predefined type default clause domain constraint collate clause domain constraint constraint name definition check constraint definition constraint characteristics Define a domain Although a DOMAIN is not strictly a type in the SQL Standard it can be informally considered a
311. ed instead of a CHECKPOINT The default is 0 which indicates no DEFRAG Useful values are between 10 to 50 Only a user with the DBA role can execute this statement This is equivalent to the connection property hsgldb defrag limit SET FILES LOG set files log statement set files log statement SET FILES LOG TRUE FALSE Sets logging of database operations on or off Turning logging off is for special usage such as temporary cache usage The default is TRUE Only a user with the DBA role can execute this statement This is equivalent to the connection property hsqgldb log data SET FILES LOG SIZE set files log size statement set files log size statement SET FILES LOG SIZE unsigned integer literal Sets the maximum size in MB of the log file to the specified value The default maximum size is 50 MB If the value is zero no limit is used for the size of the file When the size of the file reaches this value a CHECKPOINT is performed and the the log file is cleared to size 0 Only a user with the DBA role can execute this statement This is equivalent to the connection property hsqldb log_size SET FILES NIO set files nio 222 HyperSGL System Management set files nio statement SET FILES NIO TRUE FALSE Sets the access method of the data file The default is TRUE and uses the Java nio classes to access
312. eeas 221 Authentication SHINES sensere oraren oE e tote se exsequi tupcare ese eese ee pede aa ke FE Day tes ees 224 MIU Sp ME 227 vil HyperSQL HyperSQL User Guide Connection URES 4 2 causes wonsses cot osetedeses ss ee eve O pak as olie pese ga bani ede ou pase be deyo daye ro posktsnd base 227 Variables In Connection ier H 228 CONNECTION Properes E M 228 Database Properties in Connection URL and Properties 2 0 00 cece cece eee ce eeceeeceeeeaeeea essa sean eeaes 230 SQL Conformance Properties 5 e cose rete aye aste eerte gero itor tori Ebr ed ve good eue E veg eve usur ee vor UP RES en 231 Database Operations Properties ssssssesseseee ee m eH Hem emm emer hen rennen 235 Database File and Memory Properties ssessesse ee mH HI Hee 236 Crypt Properties 3 etus notice tte tu sit in ne ia aka ite un ia RE 241 ulis MR EUER 242 13 HyperSQL Network Listeners Servers sssssssesseseseee e mee mee hee ee nhe ee hene nnne 243 Listeners M 243 HyperSQL Server teksti tite ian oi ie eta bain tite ost ee eov ut vues t eee km e utut pe OOo e ci seu ee ivan tees 243 HypetSOU HTTP Ic 243 HypersOE HITP Servlet 212i Roe oL mE em Ut b PV e a ye Pye E dete 244 Seryer and Web Server Properties css scutes suwecasseovsesessve cues evo edet voe
313. entheses followed by the interval qualifier fields In the first example below COL1 and COL2 are of the same datetime type and the result is evaluated in INTERVAL YEAR TO MONTH type COLI COL2 YEAR TO MONTH the difference between two DATE or two TIEMSTAMP values in years and months CURRENT DATE COL3 DAY the number of days between the value of COL3 and the current date CURRENT DATE DATE 2000 01 01 YEAR TO MONTH the number of years and months since the beginning of this century CURRENT DATE 2 DAY the date of the day before yesterday CURRENT TIMESTAMP TIMESTAMP 2009 01 01 00 00 00 DAY 4 TO SECOND 2 days to seconds since the given date The individual fields of both datetime and interval values can be extracted using the EXTRACT function The same function can also be used to extract the time zone displacement fields of a datetime value 22 HyperSGL SQL Language EXTRACT YEAR MONTH DAY HOUR MINUTE SECOND TIMEZONE HOUR TIMEZONE MINUTE DAY OF WEEK WEEK OF YEAR FROM datetime value interval value The dichotomy between interval types based on seconds and those based on months stems from the fact that the different calendar months have different numbers of days For example the expression nine months and nine days since an event is not exact when the date of the event is unknown It can r
314. ents after the call The getMoreResults method and the getResultSet method can be used to access the ResultSet s returned by a procedure that returns one or more results If the procedure returns more than one result set the getMoreResults call moves to the next result In the example below the procedure inserts a row into the customer table It then performs the SELECT statement to return the latest inserted row as a result set Therefore the definition includes the DYNAMIC RESULT SETS 1 clause You must specify correctly the maximum number of result sets that the procedure may return CREATE PROCEDURE new customer firstname VARCHAR 50 lastname VARCHAR 50 MODIFIES SQL DATA DYNAMIC RESULT SETS 1 BEGIN ATOMIC DECLARE result CURSOR FOR SELECT FROM CUSTOMERS WHERE ID IDENTITY INSERT INTO CUSTOMERS VALUES DEFAULT firstname lastname CURRENT_TIMESTAMP OPEN result END The above procedure is called in Java using a CallableStatement Connection conn CallableStatement call conn prepareCall call new_customer cesset Sezi dye Pu SE celis set string emat call execute if call getMoreResults ResultSet result call getResultSet 154 HyperSQL SQL Invoked Routines In the example below a procedure has one IN argument and two OUT arguments The JDBC CallableStatement is used to retrieve the values returned in the OUT arguments CREATE PROCEDURE get custome
315. ents and to specify the empty string delimiter The TLS settings have been obsoleted To get your server running with TLS set system javax net ssl keyStore path to your private keystore system javax net ssl keyStorePassword secretPassword f server ssl true IN server properties or webserver properties and MAKE THE FILE OWNER READ ONLY See the TLS Encryption section of the HyperSQL User Guide paying attention to the security warning s If you are running with a private server cert then you will also need to set truststore in the your SqlTool config file location is set by the AUTH FILE variable in this file or it must be at the default location for HSOLDB OWNER Any JVM args for the invocation of the JDBC client used to verify DB instances and to shut them down SqlToolSprayer Server side System Properties should normally be set with system settings in the server webserver properties file This example specifies the location of a private trust store for TLS f encryption For multiple args put quotes around entire value If you are starting just a TLS encrypted Listener you need to uncomment this so the init scripts uses ILS to connect If using a private keystore you also need to set truststore settings in the sqltool rc file CLIENT JVMARGS Djavax net debug ssl This sample value displays useful debugging information about TLS SSL Any JVM args for
316. epresent a period of around 284 days give or take one SQL interval values are independent of any start or end dates or times However when they are added to or subtracted from certain date or timestamp values the result may be invalid and cause an exception e g adding one month to January 30 results in February 30 which is invalid JDBC has an unfortunate limitation and does not include type codes for SOL INTERVAL types Therefore for compatibility with database tools that are limited to the JDBC type codes HyperSQL reports these types by default as VARCHAR You can use the URL property hsqldb translate dti types false to override the default behaviour Arrays Array are a powerful feature of SQL 2008 and can help solve many common problems Arrays should not be used as a substitute for tables HyperSQL supports arrays of values according to the SQL 2008 Standard Elements of the array are either NULL or of the same data type It is possible to define arrays of all supported types including the types covered in this chapter and user defined types except LOB types An SQL array is one dimensional and is addressed from position 1 An empty array can also be used which has no element Arrays can be stored in the database as well as being used as temporary containers of values for simplifying SQL statements They facilitate data exchange between the SQL engine and the user s application The full range of supported syntax allows array t
317. er ELSE SET counter COALESCE counter 0 1 SET addup COALESCE addup 0 COALESCE x 0 RETURN NULL END IF END The user defined aggregate function is used in a select statement in the example below Only the first parameter is visible and utilised in the select statement SELECT udavg id FROM customers GROUP BY lastname In the example below the function returns an array that contains all the values passed for the aggregated column For use with longer arrays you can optimise the function by defining a larger array in the first iteration and using the TRIM ARRAY function on the RETURN to cut the array to size This function is similar to the built in ARRAY AGG function CREATE AGGREGATE FUNCTION array aggregate IN val VARCHAR 100 IN flag boolean INOUT buffer VARCHAR 100 ARRAY INOUT counter INT RETURNS VARCHAR 100 ARRAY CONTAINS SQL BEGIN ATOMIC IF flag THEN RETURN buffer ELSE IF val IS NULL THEN RETURN NULL END IF IF counter IS NULL THEN SET counter 0 END IF SET counter counter 1 IF counter 1 THEN SET buffer ARRAY val ELSE SET buffer counter val END IF RETURN NULL END IF END The tables and data for the select statement below are created with the DatabaseManager or DatabaseManagerSwing GUI apps You can find the SQL in the TestSelf txt file in the zip Part of the output is shown Each row of the output includes an array containing the values for the invoices
318. er OVERLAPS overlaps predicate lt overlaps predicate row value predicand OVERLAPS row value predicand gt Specify a test for an overlap between two datetime periods Each row value predicand must have two fields and the fields together represent a datetime period So the predicates is always in the form X1 X2 OVERLAPS Y1 Y2 The first field is always a datetime value while the second field is either a datetime value or an interval value If the second value is an interval value it is replaced with the sum of the datetime value and itself for example X1 x1 X2 OVERLAPS Y1 Y1 Y 2 If any of the values is NULL the result is UNKNOWN The expression is true if there is there is any overlap between the two datetime periods In the example below the period is compared with a week long period ending yesterday startdate enddate OVERLAPS CURRENT DATE 7 DAY CURRENT DATE 1 DAY IS DISTINCT is distinct predicate distinct predicate row value predicand IS NOT DISTINCT FROM row value predicand gt Specify a test of whether two row values are distinct The result of the test is either TRUE or FALSE never UNKNOWN The degree the two row value predicand must be the same Each field of the first row value predicand gt is compared to the field of the second row value predicand at the same position 115 HyperSGL Data Access and Change If one fiel
319. er Or if the query expression is used as a derived table in an enclosing query expression In the example below the query is on the same table but with column renaming in the Select list The new names are used in the ORDER BY clause SELECT x y AS xysum y t z AS yzsum FROM atable AS t u v w x y z WHERE u v w ORDER BY xysum yzsum If the names xy sum or yzsum are not used the computed columns cannot be referenced in the ORDER BY list 127 HyperSGL Data Access and Change Name Resolution In a joined table if a column name appears in tables on both sides then any reference to the name must use the table name in order to specify which table is being referred to Grouping Operations Grouping Operations Grouping results in the elimination of duplicate rows A grouping operation is performed after the operations discussed above A simple form of grouping is performed by the use of DISTINCT after SELECT This eliminates all the duplicate rows rows that have the same value in each of their columns when compared to another row The other form of grouping is performed with the GROUP BY clause This form is usually used together with aggregation Aggregation Aggregation is an operation that computes a single value from the values of a column over several rows The operation is performed with an aggregate function The simplest form of aggregation is counting performed by the COUNT function Other com
320. er greater than or equal to the argument If the argument is exact numeric then the result is exact numeric with a scale of 0 If the argument is approximate numeric then the result is of DOUBLE type JDBC and Foundation BITAND BITAND lt num value expr 1 gt lt num value expr 2 BITAND bit value expr 1 bit value expr 2 BITANDNOT 178 HyperSGL Built In Functions BITANDNOT num value expr 1 gt num value expr 2 BITANDNOT bit value expr 1 bit value expr 2 BITNOT BITNOT num value expr 1 BITNOT bit value expr 1 BITOR BITOR num value expr 1 gt num value expr 2 BITOR bit value expr 1 gt bit value expr 2 BITXOR BITXOR num value expr 1 num value expr 2 BITXOR bit value expr 1 bit value expr 2 These functions bit operations on two values or in the case of BITNOT on a single values The values are either integer values or bit strings The result is an integer value of the same type as the arguments or a bit string of the same length as the argument Each bit of the result is formed by performing the operation on corresponding bits of the arguments The names of the function indicate NOT OR AND XOR operations The BITANDNOT performs NOT on the second argument then performs AND on result and the first argument HyperSQL COS COS num value expr gt Returns the cosine of the argument an angle expressed in radi
321. er http hsqldb svn sourceforge net viewvc hsqldb base tags or you can export a snapshot or check out a work area using Subversion client You must locally install the DocBook set of image files which are available for download from Sourceforge The gen docs task target will tell you of a Gradle task that you can use to download and install them automatically This Gradle task installDbImages will tell you how to edit a properties text file to tell it what directory to install the files into Command line as opposed to GUI builders can use the Gradle P switch to set the property instead of editing if they prefer Youcan optionally install the entire DocBook style sheets instead of just the DocBook images within it character entity definitions and RNG schema file to speed up doc build times and minimize dependency of future builds upon network or Internet n intermediate approach would be to install these resources onto an HTTP server or shared network drive of your own See the comments at the top of the file build xml in the HyperSQL build directory about where to obtain these things and how to hook them in The same Gradle task installDbImages explained above can download and install the entire stylesheet bundle this option is offered the first time that you run the installDbImages task Tip If running Gradle you probably want to turn logging up to level info for generation and validation tasks because the
322. ere are several predefined collations These collations belong to INFORMATION SCHEMA However when they are referenced in a statement there is no need for a schema prefix There is a separate name space for collations Collations for a large number of languages are supported by HyperSQL HyperSQL support a default collation for the whole database Optionally a different collation can be specified for each table column that is defined as CHAR or VARCHAR Also a different collation can be used in an ORDER BY clause When comparing two strings all collation pad the shorter string with spaces before comparing the two strings of equal length You can change the default database collation with one that does not pad the string with spaces before comparison See SET DATABASE COLLATION statement in the System Management chapter Distinct Types A distinct user defined TYPE is simply based on a built in type A distinct TYPE is used in table definitions and in CAST statements Distinct types share a name space with domains Domains A DOMAIN is a user defined type simply based on a built in type A DOMAIN can have constraints that limit the values that the DOMAIN can represent A DOMAIN can be used in table definitions and in CAST statements Distinct types share a name space with domains Number Sequences A SEQUENCE object produces INTEGER values in sequence The SEQUENCE can be referenced in special contexts only within certain SQL sta
323. eric literal unsigned numeric literal exact numeric literal approximate numeric literal exact numeric literal unsigned integer period unsigned integer period unsigned integer sign plus sign minus sign lt approximate numeric literal gt lt mantissa gt E lt exponent gt lt mantissa gt lt exact numeric literal gt lt exponent gt lt signed integer gt 101 HyperSGL Data Access and Change signed integer sign unsigned integer unsigned integer digit The type of an exact numeric literal without a decimal point is INTEGER BIGINT or DECIMAL depending on the value of the literal the smallest type that can represent the value is the type The type of an exact numeric literal with a decimal point is DECIMAL The precision of a decimal literal is the total number of digits of the literal The scale of the literal is the total number of digits to the right of the decimal point The type of an approximate numeric literal is DOUBLE An approximate numeric literal always includes the mantissa and exponent separated by E 12 84535 TIZES boolean literal boolean literal lt boolean literal gt TRUE FALSE UNKNOWN T The boolean literal is one of the specified keywords datetime and interval literal datetime and interval literal lt datetime literal
324. erpreted as upper case like any named SQL object Only for backwards compatibility we do make an exception for the special user name SA but you should always use upper case SA nevertheless When you re finished playing exit with the command q If you changed the SA password then you need to update the password in the sqlt ool rc file accordingly 258 HyperSGL HyperSQL on UNIX You can of course also access the database with any JDBC client program You will need to modify your classpath to include hsqldb jar as well as your client class es You can also use the other HSQLDB client programs such asorg hsqldb util DatabasManagerSwing a graphical client with a similar purpose to Sq1Tool You can use any normal UNIX account to run the JDBC clients including SqlTool as long as the account has read access to the sqltool jar file and to an sqltool rc file See the Utilities Guide about where to put sqltool rc how to execute sql files and other Sql Tool features Create additional Accounts Connect to the database as SA or any other Administrative user and run CREATE USER to create new accounts for your catalog HSQLDB accounts are database catalog specific not List ener specific In SQL compliant databases all database objects are created in a schema If you don t specify a schema then the new object will be created in the default schema To create a database object your account the account that you
325. erver Servlet java to see the details Both HTTP Server and Servlet modes can only be accessed using the JDBC driver at the client end They do not provide a web front end to the database The Servlet mode can serve only a single database Please note that you do not normally use this mode if you are using the database engine in an application server In this situation connections to a catalog are usually made in process or using a separate Server Connecting to a Database Server When a HyperSQL server is running client programs can connect to it using the HSQLDB JDBC Driver contained in hsqlab jar Full information on how to connect to a server is provided in the Java Documentation for HyperSGL Running and Using HyperSQL JDBCConnection located in the doc apidocs directory of HSQLDB distribution A common example is connection to the default port 9001 used for the hsql protocol on the same machine Example 1 1 Java code to connect to the local hsql Server try Class forName org hsqldb jdbc JDBCDriver catch Exception e System err println ERROR failed to load HSQLDB JDBC driver e printStackTrace return Connection c DriverManager getConnection jdbc hsqldb hsql localhost xdb SA If the HyperSQL HTTP server is used the protocol is http and the URL will be different Example 1 2 Java code to connect to the local http Server Connection c DriverManager getC
326. ery expression body query term query expression body UNION EXCEPT ALL DISTINCT corresponding spec query term query term query primary query term INTERSECT ALL DISTINCT corresponding spec query term query primary simple table left paren query expression body order by clause result offset clause fetch first clause right paren simple table query specification gt lt table value constructor gt explicit table gt lt explicit table gt TABLE lt table or query name gt lt corresponding spec CORRESPONDING BY left paren column name list lt right paren gt A query term anda query primary can be a SELECT statement an explicit table ora table value constructor The CORRESPONDING clause is optional If it is not specified then the query term and the query primary must have the same number of columns If CORRESPONDING is specified the two sides need not have the same number of columns If no column list is used with CORRESPONDING then all the column names that are common in the tables on two sides are used in the order in which they appear in the first table If a columns list is used it allows you to select only some columns of the tables on the left and right side to create the new table In the example below the columns named u and v from the two SELECT statements are
327. es ranking FROM t JOIN tl on t id tl tid UPDATE t SET scores 2 123 names 2 Reds WHERE id 10 Array Operations Several SQL operations and functions can be used with arrays CONCATENATION Array concatenation is performed similar to string concatenation All elements of the array on the right are appended to the array on left array concatenation gt array value expression 1 concatenation operator array value expression 2 concatenation operator FUNCTIONS Four functions operate on arrays Details are described in the Built In Functions chapter CARDINALITY left paren array value expression right paren MAX CARDINALITY left paren array value expression right paren Array cardinality and max cardinality are functions that return an integer CARDINALITY returns the element count while MAX CARDINALITY returns the maximum declared cardinality of an array TRIM ARRAY left paren array value expression comma numeric value expression right paren The TRIM ARRAY function returns a copy of an array with the specified number of elements removed from the end of the array The array value expression can be any expression that evaluates to an array ARRAY SORT left paren array value expression right paren The ARRAY SORT function returns a sorted copy of an array NULL elements appear at the beginning of the new array This function is a HyperSQL ex
328. es simple row count queries in the form of SELECT COUNT FROM table and returns the result immediately this optimisation does not take place in MVCC mode HyperSQL can use an index on a column for SELECT MAX column FROM table and SELECT MIN column FROM lt table gt queries There should be an index on the column and the query can have a WHERE condition on the same column In the example below the maximum value for the TB COL3 below 1000000 is returned SELECT MAX TB COL3 FROM TB WHERE TB COL 1000000 HyperSQL can use an index for simple queries containing DISTINCT or GROUP BY to avoid checking all the rows of the table Note that indexes are always used if the query has a condition regardless of the use of DISTINCT or GROUP BY This particular optimisation applies to cases in which all the columns in the SELECT list are from the same table and are covered by a single index and any join or query condition uses this index For example with the large table below a DISTINCT or GROUP BY query to return all the last names can use an the index on the TC LASTNAME column Similarly a GROUP BY query on two columns can use an index that covers the two columns TC is a very large table SELECT DISTINCT LASTNAME FROM TC WHERE TC LASTNAME gt F SELECT STATE LASTNAME FROM TC GROUP BY STATE LASTNAME Indexes and ORDER BY OFFSET and LIMIT HyperSQL can use an index o
329. ession in which the statement was used AT TIME ZONE modifies the field values of the datetime operand This is done by the following procedure 1 determine the corresponding datetime at UTC 2 find the datetime value at the given time zone that corresponds with the UTC value from step 1 Example a TIME 12 00 00 AT TIME ZONE INTERVAL 1 00 HOUR TO MINUTE If the session s time zone displacement is 8 00 then in step 1 TIME 12 00 00 is converted to UTC which is TIME 20 00 00 0 00 In step 2 this value is expressed as TIME 21 00 00 1 00 Example b TIME 12 00 00 5 00 AT TIME ZONE INTERVAL 1 00 HOUR TO MINUTE Because the operand has a time zone the result is independent of the session time zone displacement Step 1 results in TIME 17 00 00 0 00 and step 2 results in TIME 18 00 00 1 00 Note that the operand is not limited to datetime literals used in these examples Any valid expression that evaluates to a datetime value can be the operand Type Conversion CAST is used to for all other conversions Examples CAST value AS TIME WITHOUT TIME ZONE CAST value AS TIME WITH TIME ZONE In the first example if value has a time zone component it is simply dropped For example TIME 12 00 00 5 00 is converted to TIME 12 00 00 In the second example if value has no time zone component the current time zone displacement of the session is added
330. ession to read uncommitted data that violates database integrity constraints but has not yet been checked CONSTRAINT table constraint definition table constraint definition constraint name definition lt table constraint constraint characteristics 55 HyperSQL Schemas and Database Objects table constraint gt unique constraint definition referential constraint definition check constraint definition Three kinds of constraint can be defined on a table UNIQUE including PRIMARY KEY FOREIGN KEY and CHECK Each kind has its own rules to limit the values that can be specified for different columns in each row of the table UNIQUE unique constraint definition unique constraint definition unique specification left paren unique column list right paren UNIQUE VALUE LA unique specification UNIQUE PRIMARY KEY lt unique column list gt lt column name list gt A unique constraint is specified on a single column or on multiple columns On each set of columns taken together only one UNIQUE constraint can be specified Each column of a PRIMARY KEY constraint has an implicit NOT NULL constraint If UNIQUE VALUE is specified the constraint created on all columns of the table FOREIGN KEY referential constraint definition lt referential constraint definition gt FOREIGN KEY lt lef
331. estricting access according to the source address of the incoming connection request This is efficient because the database engine never even gets the request until it is approved by the ACL filter code The sample file sample acl txt in your HyperSQL distribution explains how to write an ACL file Sid acl txe 826 2009 01 17 05 04 522 unsaved S Sample HyperSQL Network Listener ACL file Specify allow and deny rules For address specifications individual addresses host names and network addresses with bit suffix are allowed but read the caveat about host names below under the sample localhost rule Blank lines ignored Lines with as the first non whitespace character are ignored allow 2001 db8 32 250 HyperSGL HyperSQL Network Listeners Servers Allow this 32 bit ipv4 subnet allow localhost You should use numerical addresses in ACL files unless you are certain that the name will always be known to your network address resolution system assume that you will lose Internet connectivity at some time With a default name resolution setup on UNIX you are safe to use names defined in your etc hosts file deny 192 168 101 253 Deny a single IP address In our example 192 168 101 0 24 is our local organizational network 192 1069 101 252 is the IP address of our Interu s PU The Intern does not have permission to access our databases directly allow 192 168 101 0 24 An
332. ethod is defined like this public static boolean accessMethod String param return param null amp amp param length gt 6 It is possible to replace the default password authentication completely with a function that uses external authentication servers such as LDAP This function is called each time a user connects to the database SET DATABASE AUTHENTICATION FUNCTION set database authentication function lt set database authentication function statement gt SET DATABASE AUTHENTICATION FUNCTION lt external body reference gt NONE The routine body is an external Java function reference This function has three String parameters The first parameter is the unique name of the database the second parameter the user name and the third parameter the password External authentication can be used in two different patterns In the first pattern user names must be stored in the database In the second pattern user names shouldn t be stored in the database and any names that are stored in the database are ignored In both patterns the username and password are checked by the authentication function If the function throws a runtime exception then authentication fails In the first pattern the function always returns null if authentication is successful In the second pattern the function returns a list of role names that have been granted to the user These roles must match the ROLE objects that have been define
333. eturned by some query expressions is updatable HSQLDB supports core SQL updatability features plus some enhancements from the SQL optional features A query expression is updatable if it is a SELECT from a single underlying base table or updatable view either directly or indirectly A SELECT statement featuring DISTINCT or GROUP BY or FETCH LIMIT OFFSET is not updatable In an updatable query expression one or more columns are updatable An updatable column is a column that can be traced directly to the underlying table Therefore columns that contain expressions are not updatable Examples of updatable query expressions are given below The view V is updatable when its query expression is updatable The SELECT statement from this view is also updatable SELECT A B FROM T WHERE C 5 SELECT A B FROM SELECT FROM T WHERE C 10 AS TT WHERE TT B 10 CREATE VIEW V X Y AS SELECT A B FROM T WHERE C 0 AND B 10 SELECT X FROM V WHERE Y 5 If a cursor is declared with the SQL qualifier FOR UPDATE OF column name list then only the stated columns in the result set become updatable If any of the stated columns is not actually updatable then the cursor declaration will not succeed If the SQL qualifier FOR UPDATE is used then all the updatable columns of the result set become updatable If a cursor is declared with FOR READ ONLY then it is not updatable In HSQLDB if FOR READ ONLY or FOR UPDATE is not used then all t
334. eturns internal ID of a lob as a BIGINT value Lob ID s are unique and never reused The column reference is the name of the column or variable or argument which is a CLOB or BLOB Returns null if the value is null HyperSQL ROWNUM ROWNUM ROW NUMBER ROW NUMBER OVER Returns the current row number from 1 being processed in a select statement This has the same semantics as the ROWNUM pseudo column in Oracle syntax mode but can be used in any syntax mode The function is used in a SELECT of DELETE statement The ROWNUM of a row is incremented as the rows are added to the result set It is therefore possible to use a condition such as WHERE ROWNUMO lt 10 but not ROWNUMO gt 10 or ROWNUM 10 The ROW NUMBER OVER alternative performs the same function and is included for compatibility with other database engines HyperSQL 197 HyperSQL Chapter 11 System Management Fred Toussi The HSQL Development Group Revision 5039 Copyright 2002 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Mode of Operation and Tables HyperSQL has many modes of operation and features that allow it to be used in very different scenarios Levels of memor
335. ewer distributions always document the Java version for the build in the file doc index htm1 If that still doesn t help then you can just try your hsqldb jar and see if it works or build your own To use the supplied hsqldb jar just skip to the next section of this document Otherwise build a new hsqldb jar Procedure 14 1 Building hsqldb jar 1 Ifyou don t already have Ant download the latest stable binary version from http ant apache org cd to where you want Ant to live and extract from the archive with unzip path to file zip or tar szi path to file tar gz or bunzipz c pathy to file tar bzz tar zzi Everything will be installed into a new subdirectory named apache ant version You can rename the directory after the extraction if you wish 2 Set the environmental variable JAVA HOME to the base directory of your Java JRE or SDK like export JAVA HOME JAVA HOME usr java j2sdk1 4 0 The location is entirely dependent upon your variety of UNIX Sun s rpm distributions of Java normally install to usr java something Sun s System V package distributions of Java including those that come with Solaris normally install to usr something with a sym link from usr java to the default version so for Solaris you will usually set JAVA HOME to usr java 3 Remove the existing file HSQLDB HOME lib hsqldb jar 4 cdto HSOLDB HOME build Mak
336. ext data and all of the indexes The Text table data source can always be reassigned to a different file if necessary The commands are needed to set up a TEXT table as detailed in the Text Tables chapter HyperSGL SQL Language With all in memory databases both MEMORY table and CACHED table declarations are treated as declarations for non persistent memory tables In the latest versions of HyperSQL TEXT table declarations are allowed in all in memory databases The default type of tables resulting from future CREATE TABLE statements can be specified with the SOL command SET DATABASE DEFAULT TABLE TYPE CACHED MEMORY j The type of an existing table can be changed with the SOL command SET TABLE table name TYPE CACHED MEMORY SQL statements access different types of tables uniformly No change to statements is needed to access different types of table Lob Data Lobs are logically stored in columns of tables Their physical storage is a separate lobs file This file is created as soon as a BLOB or CLOB is inserted into the database The file will grow as new lobs are inserted into the database In version 2 x the lobs file is never deleted even if all lobs are deleted from the database In this case you can delete the lobs file after a SHUTDOWN Short Guide to Data Types Most other RDBMS do not conform to the SQL Standard in all areas but they are gradually moving towards Standard conformanc
337. f the ResultSet interface which have a Calendar parameter can be used with a Calendar argument to retrieve the values JDBC has an unfortunate limitation and does not include type codes for SQL datetime types that have a TIME ZONE property Therefore for compatibility with database tools that are limited to the JDBC type codes HyperSQL reports these types by default as datetime types without TIME ZONE You can use the URL property hsqldb translate dti types false to override the default behaviour Interval Types Interval types are used to represent differences between date time values The difference between two date time values can be measured in seconds or in months For measurements in months the units YEAR and MONTH are available while for measurements in seconds the units DAY HOUR MINUTE SECOND are available The units can be used individually or as arange An interval type can specify the precision of the most significant field and the second fraction digits of the SECOND field if it has a SECOND field The default precision is 2 The default second precision is 0 interval type INTERVAL interval qualifier interval qualifier start field TO end field single datetime field start field non second primary datetime field left paren interval leading field precision right paren end field non second primary datetime field SECOND left paren interval f
338. f the columns of the constraint it conforms to the constraint A unique constraint on multiple columns cl c2 c3 means that in no two rows the sets of values for the columns can be equal unless at lease one of them is NULL Each single column taken by itself can have repeat values in different rows The following example satisfies a UNIQUE constraint on the two columns Example 4 4 Column values which satisfy a 2 column UNIQUE constraint l 2 2 1 2 2 NULL 1 NULL 1 1 NULL NULL NULL NULL NULL If the SET DATABASE SQL UNIQUE NULLS FALSE has been set then if not all the values set of columns are null the not null values are compared and it is disallowed to insert identical rows that contain at least one not null value PRIMARY KEY A PRIMARY KEY constraint is equivalent to a UNIQUE constraint on one or more NOT NULL columns Only one PRIMARY KEY can be defined in each table FOREIGN KEY A FOREIGN key constraint is based on an equality comparison between values of specific columns taken together of each row with the values of the columns of a UNIQUE constraint on another table or the same table The result of the comparison must never be false can be unknown A special form of FOREIGN KEY constraint based on its CHECK clause allows the result to be unknown only if the values for all columns are NULL A FOREIGN key can be declared only if a UNIQUE constraint exists on the referenced columns Constraints share a name spac
339. fetch first row count USING INDEX A slicing operation takes the result set that has been already processed and ordered It then discards the specified number of rows from the start of the result set and returns the specified number of rows after the discarded rows The offset row count and fetch first row count can be constants dynamic variables routine parameters or routine variables The type of the constants must be INTEGER SELECT a b FROM atable WHERE d 5 ORDER BY absum OFFSET 3 FETCH 2 ROWS ONLY SELECT a b FROM atable WHERE d 5 ORDER BY absum OFFSET 3 LIMIT 2 alternative keyword When the FETCH keyword is used the specified number of rows must be at least 1 otherwise an error is returned This behaviour is consistent with the SQL Standard When the LIMIT keyword is used the specified number of rows can be zero which means return all rows no LIMIT In MySQL and PostgreSQL syntax modes zero limit means no rows empty result If there is an index on all the columns specified in the ORDER BY clause it is normally used for slicing In some queries an index on another column may take precedence It is possible to add USING INDEX to the end of the slicing clause to force the use of the index for ordering and slicing Data Change Statements Delete Statement DELETE FROM delete statement searched 131 HyperSGL Data Access and Change delete statement searched DELETE F
340. fication gt lt default specification gt lt null specification gt NULL lt default specification gt DEFAULT Specify a value whose data type or value is inferred from its context DEFAULT is used for assignments to table columns that have a default value or to table columns that are generated either as an IDENTITY value or as an expression NULL can be used only in a context where the type of the value is known For example a NULL can be assigned to a column of the table in an INSERT or UPDATE statement because the type of the column is known But if NULL is used in a SELECT list it must be used in a CAST statement Value Expression Value expression is a general name for all expressions that return a value Different types of expressions are allowed in different contexts value expression primary 104 HyperSGL Data Access and Change value expression primary value expression primary fie parenthesized value expression nonparenthesized value expression primary parenthesized value expression left paren value expression right paren nonparenthesized value expression primary unsigned value specification column reference set function specification gt scalar subquery gt case expression cast specification gt next value expression current value expression gt lt routine invocation gt Specify a value that is syntactically self de
341. first column of the result indicates the calculated generation of each dog ranging from first to fourth generation CREATE TABLE pptree pid INT id INT INSERM INTO SE PETE C WANKING NU S GLA CESAR 4 5 5 6 6 Gnas WITH RECURSIVE tree gen par child AS VALUES 1 CAST null as int 1 UNION SELECT gen 1 pid id FROM pptree tree WHERE pid child SELECT FROM tree GEN PAR CHILD Ji anal 2 i 2 2 ul 3 S 2 4 S S 6 S S 7 4 4 5 if recursive queries become complex they also become very difficult to develop and debug HyperSQL provides an alternative to this with user defined SQL functions which return tables Functions can perform any complex repetitive task with better control using loops variables and if necessary recursion Query Expression A query expression consists of an optional WITH clause and a query expression body The optional WITH clause lists one or more named ephemeral tables that can be referenced just like the database tables in the query expression body 129 HyperSGL Data Access and Change query expression with clause query expression body A query expression body refers to a table formed by using UNION and other set operations The query expression body is evaluated from left to right and the INTERSECT operator has precedence over the UNION and EXCEPT operators A simplified BNF is given below qu
342. first connection to an existing database readonly true files readonly true hsqldb lock file false hsqldb sqllog 1 3 These specific property value pairs override the existing database properties For example a normal database is opened as readonly or the lock file is not created or the sqllog level is set to a value between 1 and 3 Management of properties has changed since version 1 8 The old SET PROPERTY statement does not change a property and is ignored The statement is retained to simplify application upgrades In the example URL below two properties are set for the first connection to a new database jdbc hsqldb file enrolments hsqldb cache rows 10000 hsqldb nio data file false In the table below database properties that can be used as part of the URL or in connection properties are listed For each property that can also be set with an SQL statement the statement is also given These statements are described more extensively in the System Management chapter Table 12 9 Validity Check Property Name Description check props checks the validity of the connection properties If the property is true every database property that is specified on the URL or in connection properties is checked and if it is not used correctly an error is returned this property cannot be set with an SQL statement 230 HyperSGL Properties SQL Conformance Properties Table 12 10 SQL Keyword Use
343. fline Backup Example rettet pe ert Exe up e al tup E pese uu Duo dolo ab po kaa e 201 11 3 Listing Backup with DbBacku p o csccccccsedhscccssvce ses sseteves dees reuse eeu tie eee pese ano n ake re kankan ENT RE 202 11 4 Restoring a Backup with DbBackup sssse HH em He mI HI he een 202 11 5 Finding foreign key rows with no parents after a bulk import 221 13 1 Exporting certificate from the server s keystore sese mH Hee emere 248 13 2 Adding a certificate to the client keystore HH e nr 248 13 3 Specifying your own trust store to a JDBC client sssssssses e 248 13 4 Getting a pem style private key into a JKS keystore cece cece ee eea een eeneeeeeeeees 249 13 5 Validating and Testing an ACL cD cic iie ees ttr eye renes ott Roe pe re EE pa pa eR EE Ak RE eM a 251 14 1 example sgltool re st nzd 1 1 etie e ake Fok pase twe EEDE se ia pi Le RI repa esr D EREE PPP ERE A Si 261 15 1 Using CACHED tables for the LOB schema seem HI He hee herr 268 15 2 MainInvoker Example iii teepet ooo seke eyes te best este bate kek on aene l mol RE kab tuse dre Dr S m do a 270 15 3 HyperSQL Snapshot Repository Definition sese Hee mH hene hen nnne nre 275 15 4 Sample Snapshot Ivy Dependency scesie eee cicer sede beksn eee e eto see kane EKE se e BEEN an rakwen rubr Dus 276 15 5 Sample Snapshot Maven Dependency sse em enm emere 276 15 6 Sa
344. for the column It also conforms to any additional integrity constraints that are defined as CHECK constraints in domains or tables Types can be explicitly converted using the CAST expression but in most expressions they are converted automatically Data is returned to the user or the application program as a result of executing SQL statements such as query expressions or function calls All statements are compiled prior to execution and the return type of the data is known after compilation and before execution Therefore once a statement is prepared the data type of each column of the returned result is known including any precision or scale property The type does not change when the same query that returned one row returns many rows as a result of adding more data to the tables Some SQL functions used within SQL statements are polymorphic but the exact type of the argument and the return value is determined at compile time When a statement is prepared using a JDBC PreparedStatement object it is compiled by the engine and the type of the columns of its ResultSet and or its parameters are accessible through the methods of PreparedStatement Numeric Types TINYINT SMALLINT INTEGER BIGINT NUMERIC and DECIMAL without a decimal point are the supported integral types They correspond respectively to byte short int long BigDecimal and BigDecimal Java types in the range of values that they can represent NUMERIC and DECIMAL are equi
345. for user objects If a reserved word is enclosed in double quote characters it becomes a quoted identifier and can be used for database objects Case sensitivity rules for identifiers can be described simply as follows all parts of SQL statements are converted to upper case before processing except identifiers in double quotes and strings in single quotes identifiers both unquoted and double quoted are then treated as case sensitive most database engines follow the same rule except MySQL and in some respects MS SQLServer CASCADE or RESTRICT drop behavior drop behavior CASCADE RESTRICT The drop behavior is a required element of statements that drop a SCHEMA or a schema object If drop behavior is not specified then RESTRICT is implicit It determines the effect of the statement if there are other objects in the catalog that reference the SCHEMA or the schema object If RESTRICT is specified the statement fails if there are referencing objects If CASCADE is specified all the referencing objects are modified or dropped with cascading effect Whether a referencing object is modified or dropped depends on the kind of schema object that is dropped IF EXISTS drop condition HyperSQL if exists clause IF EXISTS This clause is not part of the SQL standard and is a HyperSQL extension to some commands that drop objects schemas tables views sequences and indexes If it is specified
346. fre L tike ai ERE 99 Syntax Elements eropa ea d estote kiye EE ak e op ee a ke NA a e eyes ei EK Des 99 Eiter MC cm 99 Idest SERE TTL I 103 Value EXptEeSSIOD se e becesese tta eo revers oov ones Nor Se Ula vule dla s P ddies avoka A ere vus o De kiles AY ake 104 lucu Rm 111 Aberepate FUNCHONS ones tecto pre costes e sese kisa eka aide duree fedus edic uv Deos eed eoe but d drop a era 116 Other Syntax Elements ge me 117 Data ACcess Statements rresia ne de enan E a E E N E E E TTEA 119 Select Statement EE 120 Table cere droits ponn ena vre E A A A EE EES 120 SUDQUCLY erp r EE E N E O O 120 Query SpeciNCaANON MN nnn 121 Table EX pression e reet mea tele w We da aa REA REEE I EINE DEA e kn T tees ONAE TOR e pw 121 Table Primary ee trett ri deteste vet eder kip ra kone beton re E kise e ora e ke fatra pete gute ayen set one 122 BONUM M H PT 124 SEIECHON A kile a 126 Projection creeo ran ak fo die a oo wives dotate dailies S ke SA DO guste A due EE 126 Computed ColUIDS avem PV 127 Naming aoise oore rU 127 Grouping cin MEER 128 JAPPIOPALlOD e foste n tye kyes dnbie soi eee oo eee consulto redi Depa ved es DIR aee teens Lada ees seed uua 128 Set Operations nS 128 With Clause and Recursive Queries llilllee lele ee tete aaa aa aaa anana aa eee asasen ensesoseososoosoesososoosoeooone 128 Query EXpteSSION
347. gger with two DELETE statements one for each table Views that have an INSTEAD OF trigger are called TRIGGER INSERTABLE TRIGGER UPDATABLE etc according to the triggers that have been defined Views share a name space with tables Constraints A CONSTRAINT is a child schema object and can belong to a DOMAIN or a TABLE CONSTRAINT objects can be defined without specifying a name In this case the system generates a name for the new object beginning with SYS Ina DOMAIN CHECK constraints can be defined that limits the value represented by the DOMAIN These constraints work exactly like a CHECK constraint on a single column of a table as described below In a TABLE a constraint takes three basic forms CHECK A CHECK constraint consists of a search condition that must not be false can be unknown for each row of the table The search condition can reference all the columns of the current row and if it contains a subquery other tables and views in the database excluding its own table NOT NULL 47 HyperSGL Schemas and Database Objects A simple form of check constraint is the NOT NULL constraint which applies to a single column UNIQUE A UNIQUE constraint is based on an equality comparison of values of specific columns taken together of one row with the same values from each of the other rows The result of the comparison must never be true can be false or unknown If a row of the table has NULL in any o
348. gt minus sign months value months value day time literal lt day time interval gt time interval gt lt day time interval gt lt days value gt lt space gt lt hours value gt lt colon gt lt minutes value gt lt colon gt lt seconds value gt lt time interval gt lt hours value gt lt colon gt lt minutes value gt lt colon gt lt seconds value gt lt minutes value gt lt colon gt lt seconds value gt lt seconds value gt lt years value gt lt datetime value gt lt months value gt lt datetime value gt lt days value gt lt datetime value gt lt hours value gt lt datetime value gt lt minutes value gt lt datetime value gt lt seconds value gt lt seconds integer value gt lt period gt lt seconds fraction gt lt seconds integer value gt lt unsigned integer gt lt seconds fraction gt lt unsigned integer gt lt datetime value gt lt unsigned integer gt The type of a datetime or interval type is specified in the literal The fractional second precision is the number of digits in the fractional part of the literal Details are described in the SQL Language chapter DATE 2008 08 08 TIME W20 108 084 TIMESTAMP 2008 08 08 20 08 08 235 INTERVAL 10 DAY INTERVAL 08 08 MINUTE TO SECOND References etc References are identifier chains which can be a single identifiers
349. hat is performed and no further data change takes place on the view The trigger action can include all the statements that are necessary to change the data in the tables that underlie the view or even other tables such as audit tables With the use of INSTEAD OF triggers a read only view can effectively become updatable or insertable into Trigger Properties A trigger is declared on a specific table or view Various trigger properties determine when the trigger is executed and how Trigger Event The trigger event specifies the type of SQL statement that causes the trigger to execute Each trigger is specified to execute when an INSERT DELETE or UPDATE takes place The event can be filtered by two separate means For all triggers the WHEN clause can specify a condition against the rows that are the subject of the trigger together with the data in the database For example a trigger can activate when the size of a table becomes larger than a certain amount Or it can activate when the values in the rows being modified satisfy certain conditions An UPDATE trigger can be declared to execute only when certain columns are the subject of an update statement For example a trigger declared as AFTER UPDATE OF datecolumn will activate only when the UPDATE statement that is executed includes the column datecolumn as one of the columns specified in its SET statements Granularity A statement level trigger is performed once for the executed
350. he INFORMATION SCHEMA SYSTEM SESSIONS table contains the list of open sessions their unique ids and the statement currently executed or waiting to be executed by each session For each session it displays the list of sessions that are waiting for it to commit or the session that this session is waiting for Session and Transaction Control Statements ALTER SESSION 35 HyperSGL Sessions and Transactions alter session statement alter session statement ALTER SESSION numeric literal CLOSE RELEASE alter current session statement ALTER SESSION RESET ALL RESULT SETS TABLE DATA The alter session statement is used by an administrator to close another session or to release the transaction in another session When a session is released its current transaction is terminated with a failure The session remains open This statement is different from the other statements discussed in this chapter as it is not used for changing the settings of the current session The session ID is used as a numeric literal in this statement The administrator can use the INFORMATION SCHEMA SYSTEM SESSIONS table to find the session IDs of other sessions The alter current session statement is used to clear and reset different states of the current session When ALL is specified the current transaction is rolled back the sessio
351. he Derby Compatibility Apache Derby supports a smaller subset of the SQL Standard compared to HyperSQL Applications can be ported to HyperSQL without difficulty Use MVCC with set database transaction control statement if your application is multi user HyperSQL supports Java language functions and stored procedures with the standard syntax which is similar to the way Derby supports these features Oracle Compatibility Recent versions of Oracle support Standard SQL syntax for outer joins and many other operations In addition HyperSQL features a setting to support Oracle syntax and semantics for the most widely used non standard features Use set database sql syntax ORA statement to enable support for some non standard syntax of Oracle Use MVCC with set database transaction control statement if your application is multi user Fine control over MVCC deadlock avoidance is provided by the set database transaction rollback on conflict statement and the corresponding hsqgldb tx conflict rollback connection property If your application relies on Oracle behaviour for nulls in multi column UNIQUE constraints use set database sql unique nulls statement to change the default If you use the non standard concatenation of possibly NULL values in your select statements you may need to change the setting for set database sql concat nulls statement Many Oracle functions are supported including no arg functions such
352. he ELEMENT TYPES view When a row of the COLUMNS or other view indicates that the type of the object is an ARRAY type then there is a corresponding entry for this row in the ELEMENT TYPES view The following columns in the ELEMENTS TYPES view identify the database object whose data type is being described OBJECT CATALOG OBJECT SCHEMA OBJECT NAME OBJECT TYPE COLLECTION TYPE IDENTIFIER The last column s counterpart in the COLUMNS view is named differently as DTD IDENTIFIER So in order to determine the array element type of a column an equi join between the COLUMNS and ELEMENT TYPES tables on the six listed columns in the ELEMENT TYPES view and their counterparts in the COLUMNS view is needed Product Information A group of views including SQL IMPLEMENTATION INFO SQL FEATURES SQL SIZING and others cover the capabilities of HyperSQL in detail These views hold static data and can be explored even when the database is empty Operations Information There are some HyperSQL custom views cover the current state of operation of the database These include SYSTEM CACHEINFO SYSTEM SESSIONINFO and SYSTEM SESSIONS views SQL Standard Views The following views are defined by the SQL Standard and supported by HyperSQL The columns and contents exactly match the Standard requirements ADMINISTRABLE ROLE AUTHORIZATIONS Information on ROLE authorizations all granted by the admin role APPLICABLE ROLES Information on ROLE authorizations for the
353. he body of an SQL invoked routine If RESTRICT is specified and the routine is already used in a a different routine or view definition an exception is raised Altering the routine changes the implementation without changing the parameters Defining recursive SQL PSM SQL functions is only possible by altering a non recursive routine body An example is given in the SQL Invoked Routines chapter An example is given below for a function defined as a Java method then redefined as an SQL function create function zero pad x bigint digits int maxsize int returns char varying 100 Specific zero pad 01 no sql deterministic language java parameter style java external name CLASSPATH org hsqldb lib StringUtil toZeroPaddedString alter specific routine zero pad 01 language sql begin atomic declare str varchar 128 set str cast x as varchar 128 set str substring 0000000000000 from 1 for digits char length str str return str end DROP drop routine statement drop routine statement DROP specific routine designator drop behavior Destroy an SQL invoked routine Sequence Creation CREATE SEQUENCE sequence generator definition sequence generator definition CREATE SEQUENCE sequence generator name sequence generator options sequence generator options sequence generator option sequence generator option sequence generator data type option
354. he order of the tables in the JOIN ON or FROM clauses For example the second query below should be faster with large tables provided there is an index on TB COL3 The reason is that TB COL3 can be evaluated very quickly if it applies to the first table and there is an index on TB COL3 TB is a very large table with only a few rows where TB COL3 4 SELECT FROM TA JOIN TB ON TA COL1 TB COL2 AND TB COL3 4 SELECT FROM TB JOIN TA ON TA COLI TB COL2 AND TB COL3 4 The general rule is to put first the table that has a narrowing condition on one ofits columns In certain cases HyperSQL 2 2 x reorders the joined tables if it is obvious that this will introduce a narrowing condition HyperSQL features automatic on the fly indexes for views and subselects that are used in a query Indexes are used when a LIKE condition searches from the start of the string Indexes are used for ORDER BY clauses if the same index is used for selection and ordering of rows It is possible to force the use of index for ORDER BY Query Processing and Optimisation HyperSQL 2 2 x changes the order of tables in a query in order to optimise processing This happens only when one of the tables has a narrowing condition and reordering does not change the result of the query Indexes and Conditions HyperSQL optimises queries to use indexes for all types of range and equality conditions including IS NULL and NOT NULL conditions Conditions
355. he same manner as in the character version If trim octet gt is not specified the 0 octet is used as default Foundation UCASE B UCASE lt char value expr gt 177 HyperSQL Built In Functions Returns a character string that is the upper case version of the char value expr gt Equivalent to SQL Foundation UPPER char value expr JDBC UPPER UPPER lt char value expr gt Returns a character string that is the upper case version of the char value expr gt Foundation Numeric Functions ABS ABS lt num value expr gt lt interval value expr gt Returns the absolute value of the argument as a value of the same type JDBC and Foundation ACOS ACOS lt num value expr gt Returns the arc cosine of the argument in radians as a value of DOUBLE type JDBC ASIN ASIN lt num value expr gt Returns the arc sine of the argument in radians as a value of DOUBLE type JDBC ATAN ATAN num value expr gt Returns the arc tangent of the argument in radians as a value of DOUBLE type JDBC ATAN2 ATAN2 num value expr 1 num value expr 2 The num value expr 1 gt and lt num value expr 2 express the x and y coordinates of a point Returns the angle in radians representing the angle coordinate of the point in polar coordinates as a value of DOUBLE type JDBC CEILING CEIL CEILING num value expr gt Returns the smallest integ
356. he time of this release HyperSQL supports the widest range of SQL standard features among all open source RDBMS Various chapters of this guide list the supported syntax When writing or converting existing SQL DDL Data Definition Language DML Data Manipulation Language or DQL Data Query Language statements for HSQLDB you should consult the supported syntax and modify the statements accordingly Some statements written for older versions may have to be modified Over 300 words are reserved by the standard and should not be used as table or column names For example the word POSITION is reserved as it is a function defined by the Standards with a similar role as String indexOf in Java HyperSQL does not currently prevent you from using a reserved word if it does not support its use or can distinguish it For example CUBE is a reserved words that is not currently supported by HyperSQL and is allowed as a table or column name You should avoid using such names as future versions of HyperSQL are likely to support the reserved words and may reject your table definitions or queries The full list of SQL reserved words is in the appendix Lists of Keywords If you have to use a reserved keyword as the name of a database object you can enclose it in double quotes HyperSQL also supports enhancements with keywords and expressions that are not part of the SQL standard Expressions suchas SELECT TOP 5 FROM SELECT LIMIT 0 10 FROM orDROP TABLE m
357. he updatable columns of the result set become updatable This relaxes the SQL standard rule that in this case limits updatability to only simply updatable SELECT statements where all columns are updatable In JDBC CONCUR READ ONLY or CONCUR UPDATABLE can be specified for the Statement parameter CONCUR_UPDATABLE is required if the returning ResultSet is to be updatable If CONCUR READ ONLY which is the default is used then even an updatable ResultSet becomes read only When a ResultSet is updatable various setter methods can be used to modify the column values The names of the setter methods begin with update After all the updates on a row are done the updateRow method must be called to finalise the row update An updatable ResultSet may or may not be insertable into In an insertable ResultSet all columns of the result are updatable and any column of the base table that is not in the result must be a generated column or have a default value In the ResultSet object a special pseudo row called the insert row is used to populate values for insertion into the ResultSet and consequently into the base table The setter methods must be used on all the columns followed by acall to insertRow Individual rows from all updatable result sets can be deleted one at a time The deleteRow is called when the ResultSet is positioned on a row 96 HyperSGL Data Access and Change While using an updatable ResultSet to modify
358. hexadecimal default is true If false treats double quotes as normal characters default is false If true adds double quotes around all fields default is false If true ignores the first line of the file character encoding for text and character fields for example encoding UTF 8 exponent to calculate rows of the text file in cache Default is 8 equivalent to exponent to calculate average size of each row in cache Default is 8 equivalent In the example below the text source of the table is set to myfile the field separator to the pipe symbol and the long varchar separator to the tilde symbol SET TABLE mytable SOURCE myfile fs vs lvs Only a user with the DBA role can execute this statement SET TABLE SOURCE HEADER set table source header statement set table source header statement SET TABLE table name SOURCE header string E EADE Set the header for the text source for a text table If this command is used the header string is used as the first line of the source file of the text table This line is not part of the table data Only a user with the DBA role can execute this statement 59 HyperSGL Schemas and Database Objects SET TABLE SOURCE on off set table source on off statement set table source on off statement SET TABLE table name SOURCE ON OFF Attach or detach a text table from its text source
359. hich build jar files with an explanation of the purposes of the different jars clean to clean up the classes directory that is created clean all to remove the old jar and doc files as well javadoc to build javadoc hsqldbmain to build a smaller jar for HSQLDB that does not contain utilities hsqljdbc to build an extremely small jar containing only the client side JDBC driver can connect only to a HyperSQL Server 288 HyperSGL Building HyperSQL Jars hsqldbmin to build a small jar that supports in process catalogs but neither running nor connecting to HyperSQL Servers sqltool to build sqltool jar which contains only the SqlTool classes Many more targets are available Run ant pand ant explainjars HSQLDB can be built in any combination of two JRE Java Runtime Environment versions and many jar file sizes A jar built with an older JRE is compatible for use with a newer JRE you can compile with Java 1 5 and run with 1 6 But the newer JDBC capabilities of the JRE will be not be available The client jar hsqljdbc jar contains only the HSQLDB JDBC Driver client The smallest engine jar hsqldbmin jar contains the engine and the HSQLDB JDBC Driver client The default size hsqldb jar also contains server mode support and the utilities The largest size hsqldbtest jar includes some test classes as well Before building the hsqldbtest jar package you should download the junit jar from http www junit org and put it
360. his has been synced and should be recoverable A write delay of 0 impacts performance in high load situations as the engine has to wait for the file system to catch up To avoid this you can set write delay down to 10 milliseconds Each time the SET FILES WRITE DELAY statement is executed with any value a sync is immediately performed Only a user with the DBA role can execute this statement This is equivalent to the connection properties hsqldb write_delay and hsqldb write_delay_millis SET FILES SCALE set files scale set files scale statement SET FILES SCALE scale value Changes the scale factor for the data file The default scale is 8 and allows 16GB of data storage capacity The scale can be increased in order to increase the maximum data storage capacity The scale values 8 16 32 64 128 256 512 1024 are allowed Scale value 1024 allows a maximum capacity of 2 TB 223 HyperSGL System Management This command can be used only when there is no data in CACHED tables This is equivalent to the connection property hsqldb cache file scale The scale factor indicates the size of the unit of storage of data in bytes For example with a scale factor of 128 a row containing a small amount of data will use 128 bytes Larger rows may use multiple units of 128 bytes Only a user with the DBA role can execute this statement This is equivalent to the connection property hsgldb cache file scal
361. html Local apidocs org hsqldb jdbc JDBCPreparedStatement html http hsqldb org doc 2 0 apidocs org hsqldb jdbc JDBCPreparedStatement html Local apidocs org hsqldb util MainInvoker html http hsqldb org doc 2 0 apidocs org hsqldb util MainInvoker html Local apidocs index html http hsqldb org doc 2 0 apidocs Local verbatim src org hsqldb server Servlet java http hsqldb org doc 2 0 verbatim src org hsqldb server Servlet java Local verbatim src org hsqldb Tokens java http hsqldb org doc 2 0 verbatim src org hsqldb Tokens java Local verbatim src org hsqldb server WebServer java http hsqldb org doc 2 0 verbatim src org hsqldb server WebServer java 294 HyperSGL HyperSQL File Links e Local verbatim src org hsqldb test TestBase java http hsqldb org doc 2 0 verbatim src org hsqldb test TestBase java e Local verbatim src org hsqldb Trigger java http hsqldb org doc 2 0 verbatim src org hsqldb Trigger java e Local verbatim src org hsqldb sample TriggerSample java http hsqldb org doc 2 0 verbatim src org hsqldb test sample TriggerSample java e Local verbatim src org hsqldb util MainInvoker java http hsqldb org doc 2 0 verbatim src org hsqldb util MainInvoker java e Local verbatim sample hsqldb cfg http hsqldb org doc 2 0 verbatim sample hsqldb cfg e Local verbatim sample acl txt http hsqldb org doc 2 0 verbatim sample acl txt e Local verbatim sample server properties
362. iddle value in the sorted list of values MAX and MIN can be performed on all types of expressions and return the minimum or the maximum value If all values are NULL the operations return NULL 116 HyperSGL Data Access and Change COUNT returns the count of all values including nulls while COUNT value expression returns the count of non NULL values COUNT with DISTINCT also accepts multiple arguments In this usage the distinct combinations of the arguments are counted Examples below SELECT COUNT DISTINCT firstname lastname FROM customer SELECT COUNT DISTINCT firstname lastname FROM customer The EVERY ANY and SOME operations can be performed on boolean expressions only EVERY returns TRUE if all the values are TRUE otherwise FALSE ANY and SOME are the same operation and return TRUE if one of the values is TRUE otherwise it returns FALSE The other operations perform the statistical functions STDDEV POP STDDEV SAMP VAR SAMP VAR POP on numeric values NULL values are ignored in calculations User defined aggregate functions can be defined and used instead of the built in aggregate functions Syntax and examples are given in the SQL Invoked Routines chapter The lt filter clause allows you to add a search condition When the search condition evaluates to TRUE for a row the row is included in aggregation Otherwise the row is not included In the example below a single query returns two differe
363. ide the maximum accessibility The database engine runs in a JVM and opens one or more in process catalogs It listens for connections from programs on the same computer or other computers on the network It translates these connections into in process connections to the databases Several different programs can connect to the server and retrieve or update information Applications programs clients connect to the server using the HyperSQL JDBC driver In most server modes the server can serve an unlimited number of databases that are specified at the time of running the server or optionally as a connection request is received A Sever mode is also the preferred mode of running the database during development It allows you to query the database from a separate database access utility while your application is running There are three server modes based on the protocol used for communications between the client and server They are briefly discussed below More details on servers is provided in the HyperSQL Network Listeners Servers chapter HyperSQL HSQL Server This is the preferred way of running a database server and the fastest one A proprietary communications protocol is used for this mode A command similar to those used for running tools and described above is used for running the server The following example of the command for starting the server starts the server with one default database with files named mydb and the public na
364. ify an integrity constraint This feature may be supported in a future versions of HyperSQL DROP ASSERTION drop assertion statement drop assertion statement DROP ASSERTION constraint name drop behavior Destroy an assertion This feature may be supported in a future versions of HyperSQL The Information Schema The Information Schema is a special schema in each catalog The SQL Standard defines a number of character sets and domains in this schema In addition all the implementation defined collations belong to the Information Schema The SQL Standard defines many views in the Information Schema These views show the properties of the database objects that currently exist in the database When a user accesses one these views only the properties of database objects that the user can access are included HyperSQL supports all the views defined by the Standard apart from a few views that report on extended user defined types and other optional features of the Standard that are not supported by HyperSQL 73 HyperSGL Schemas and Database Objects HyperSQL also adds some views to the Information Schema These views are for features that are not reported in any of the views defined by the Standard or for use by JDBC DatabaseMetaData Predefined Character Sets Collations and Domains The SQL Standard defines a number of character sets and domains in the INFORMATION SCHEMA These domains are used in the INFORMAT
365. iled and before its execution This metadata information remains constant regardless of changes to the contents of the tables used in the query expression The metadata for the JOBC ResultSet is in the form of a ResultSetMetaData object Various methods of the Result SetMet aData interface return different properties of each column of the ResultSet A result set may contain 0 or more rows The rows are determined by the execution of the query expression The setMaxRows int method of JDBC Statement allows limiting the number of rows returned by the statement This limit is conceptually applied after the result has been built and the excess rows are discarded Navigation A cursor is either scrollable or not Scrollable cursors allow accessing rows by absolute or relative positioning No scroll cursors only allow moving to the next row The cursor can be optionally declared with the SQL qualifiers 95 HyperSGL Data Access and Change SCROLL or NO SCROLL The JDBC statement parameter can be specified as TYPE FORWARD ONLY and TYPE SCROLL INSENSITIVE The JDBC type TYPE SCROLL SENSITIVE is not supported by HSQLDB The default is NO SCROLL or TYPE FORWARD ONLY When a JDBC ResultSet is opened it is positioned before the first row Using the next method the position is moved to the first row While the ResultSet is positioned on a row various getter methods can be used to access the columns of the row Updatability The result r
366. in ivy module version 2 0 gt dependency org org hsqldb name hsqldb rev SNAPSHOT Example 15 8 Sample Snapshot Groovy Dependency using Grape Grab group org hsqldb module hsqldb version SNAPSHOT Range Versioning Keeping up to date with Range Dependencies 276 HyperSQL Deployment Guide Limitation of Maven Version Range Specifiers Note that Ivy and the many systems that use Ivy underneath like Grape and Gradle supports the opening exclusive in addition to whereas Maven supports only the opening inclusive specifier See the relevant Ivy http ant apache org ivy history latest milestone ivyfile dependency html or Maven http docs codehaus org display MA VEN Dependency Mediation and Conflict Resolution Dependency MediationandConflictResolution DependencyVersionRanges documentation for details There are special cases where you should depend on a specific version instead Range Dependency Specification Examples Important For all examples below when a range pattern is given it means the latest version equal or greater than version 2 If a classifier is shown it is optional and you can skip it to get the default no classifier jar Example 15 9 Sample Range Ivy Dependency dependency org org hsqldb name hsqldb rev 2 confz j6 default I give no example here of specifying a classifier in ivy xm1 becaus
367. in different data types CHAR VARCHAR and CLOB are the character data types BINARY VARBINARY and BLOB are the binary data types BIT and BIT VARYING are the bit string types In all string functions the position of a unit of the string within the whole string is specified from 1 to the length of the whole string In the BNF char value expr gt indicates any valid SQL expression that evaluates to a character type Likewise binary value expr gt indicates a binary type and num value expr gt indicates a numeric type ASCII ASCII char value expr gt Returns an INTEGER equal to the ASCII code value of the first character of char value expr JDBC BIT LENGTH BIT LENGTH string value expression BIT LENGTH can be used with character binary and bit strings It return a BIGINT value that measures the bit length of the string Foundation See also CHARACTER LENGTH and OCTET LENGTH CHAR CHAR UNICODE code The argument is an INTEGER Returns a character string containing a single character that has the specified UNICODE code which is an integer ASCII codes are a subset of the allowed values for UNICODE code JDBC CHARACTER LENGTH CHAR LENGTH CHARACTER LENGTH char value expression USING CHARACTERS OCTETS The CHAR LENGTH or CHARACTER LENGTH function can be used with character strings while OCTET LENGTH can be used with character or binary strings and BI
368. in the lib directory alongside servlet jar which is included in the zip package If you want your code built for high performance as opposed to debugging in the same way that we make our production distributions make a file named build properties in your build directory with the contents build debug false The resulting Java binaries will be faster and smaller at the cost of exception stack traces not identifying source code locations which can be extremely useful for debugging After installing Ant on your system use the following command from the build directory Just run ant explainjars fora concise list of all available jar files ant explainjars The command displays a list of different options for building different sizes of the HSQLDB Jar The default is built using Example B 1 Buiding the standard Hsqldb jar file with Ant ant hsqldb The Ant method always builds a jar with the JDK that is used by Ant and specified in its JAVA_HOME environment variable Building for Older JDKs HyperSQL version 2 0 cannot be directly compiled or used with JDK 1 4 It may be possible to use the RetroTranslator tool to achieve this The suggested procedure is as follows First use Gradle or Ant with JDK 1 5 and build the jar Then translate the jar using RetroTranslator with backport which bundles replacement classes for concurrency control This translation should cover the concurrency features that are
369. inally contains two rows for different furniture The table reference isthe VALUES 1 conference table 14 sofa 5 coffee table expression which evaluates to a table with 3 rows When the x value for a row matches an existing row then the existing row is updated When the x value does not match the row is inserted Therefore one row of table t is updated from dining table to conference table and two rows are inserted into table t The second example uses a SELECT statement as the source of the values for the MERGE In the third example a new row in inserted into the table only when the primary key for the new row does not exist This example uses parameters and should be executed as a JDBC PreparedStatement CREATE TABLE t id INT PRIMARY KEY description VARCHAR 100 INSERT INTO t VALUES 1 dining table 2 deck chair MERGE INTO t USING VALUES 1 conference table 14 sofa 5 coffee table AS valisi s ys ON tad vasi WHEN MATCHED THEN UPDATE SET t description vals y WHEN NOT MATCHED THEN INSERT VALUES vals x vals y MERGE INTO t USING SELECT FROM tt WHERE acol 2 AS vals x y ON t id vals x WHEN MATCHED THEN UPDATE SET t description vals y WHEN NOT MATCHED THEN INSERT VALUES vals x vals y MERGE INTO t USING VALUES CAST AS INT AS vals x ON t id vals x WHEN NOT MATCHED THEN INSERT VALUES vals x Diagnostics and State HyperSQ
370. incorrect ACL entries The suggested method of creating or changing ACLs is to work with an inactive file for new ACL files just don t enable the ac1 property yet for changing an existing file just copy it to a temporary file and edit the temporary file Then use the ServerAc1 class to test it Example 13 5 Validating and Testing an ACL file java cp path to hsqldb jar org hsqldb server ServerAcl path to acl txt If the specified ACL file fails validation you will be given details about the problem Otherwise the validated rules will be displayed including the implicit default deny rules You then type in host names and addresses one per line Each name or address is tested as if it were a HyperSQL network client address using the same exact method that the HyperSQL listener will use HyperSQL listeners use this same ServerAc1 class to test incoming source addresses ServerAcl will report the rule which matches and whether access is denied or allowed to that address If you have edited a copy of an existing ACL file as suggested above then overwrite your live ACL file with your new validated ACL file Le copy your temp file over top of your live ACL file ServerAcl can berun in the same exact way described above to troubleshoot runtime access issues If you use an ACL file and a user or application can t get a connection to the database you can run ServerAc1 to quickly and definitively find if the client is being pr
371. ine body is either one or more SQL statements or a Java reference The user that defines the routine by issuing the CREATE FUNCTION or CREATE SCHEMA command must have the relevant access rights to all tables sequences routines etc that are accessed by the routine If another user is given EXECUTE privilege on the routine then there are two possibilities depending on the lt rights clause gt This clause refers to the access rights that are checked when a routine is invoked The default is SQL SECURITY DEFINER which means access rights of the definer are used therefore no extra checks are performed when the other user invokes the routine The alternative SQL SECURITY INVOKER means access rights on all the database objects referenced by the routine are checked for the invoker This alternative is not supported by HyperSQL lt routine body gt lt SQL routine spec gt lt external body reference gt lt SQL routine spec gt lt rights clause gt lt SQL routine body gt lt rights clause gt SQL SECURITY INVOKER SQL SECURITY DEFINER SQL routine body SQL routine body The routine body of a an SQL routine consists of an statement SQL routine body SQL procedure statement EXTERNAL NAME external body reference 140 HyperSQL SQL Invoked Routines External name specifies the qualified name of the Java method associated with this routine Early releases of HyperSQL 2 0
372. ine designator gt ROUTINE lt routine name gt FUNCTION lt function name gt PROCEDURE lt procedure name gt lt object privileges gt ALL PRIVILEGES action comma action lt action gt SELECT SELECT lt left paren gt lt privilege column list gt lt right paren gt DELETE INSERT lt left paren gt lt privilege column list gt lt right paren gt UPDATE lt left paren gt lt privilege column list gt lt right paren gt REFERENCES lt left paren gt lt privilege column list gt lt right paren gt USAGE TRIGGER EXECUTE lt privilege column list gt lt column name list gt lt grantee gt PUBLIC lt authorization identifier gt 92 HyperSGL Access Control The object privileges that can be used depend on the type of the object name These are discussed in the previous section For a table if privilege column list is not specified then the privilege is granted on the table which includes all of its columns and any column that may be added to it in the future For routines the name of the routine can be specified in two ways either as the generic name as the specific name HyperSQL allows referencing all overloaded versions of a routine at the same time using its name This differs from the SQL Standard which requires the use of specific routine designator to grant privilege
373. ing is specified to be called when the function is invoked CREATE FUNCTION zero pad x BIGINT digits INT maxsize INT RETURNS CHAR VARYING 100 LANGUAGE JAVA DETERMINISTIC NO SQL EXTERNAL NAME CLASSPATH org hsqldb lib StringUtil toZeroPaddedString The signature of the Java method used in the Java code but not in SQL code to create the function is given below public static String toZeroPaddedString long value int precision int maxSize The parameter and return types of the SOL routine definition must match those of the Java method according to the table below SMALLINT short or Short int or Integer 156 HyperSQL SQL Invoked Routines NUMERIC or DECIMAL BigDecimal FLOAT or DOUBLE double or Double CHAR or VARCHAR String DATE java sql Date TIME java sql Time TIMESTAMP java sql Timestamp BINARY Byte BOOLEAN boolean or Boolean ARRAY of any type java sql Array TABLE java sql ResultSet If the specified Java method is not found or its parameters and return types do not match the definition an exception is raised If more than one version of the Java method exist then the one with matching parameter and return types is found and registered If two equivalent methods exist the first one is registered This situation arises only when a parameter is a primitive in one version and an Object in another version e g Long and java lang Long When the Java method of an SQL J
374. ing non standard limitations of MySQL Win HyperSQL an UPDATE statement can update UNIQUE and PRIMARY KEY columns of a table without causing an exception due to temporary violation of constraints These constraints are checked at the end of execution therefore there is no need for an ORDER BY clause in an UPDATE statement MySQL foreign key constraints are not enforced by the default MyISAM engine Be aware of the possibility of data being rejected by HyperSQL due to these constraints With HyperSQL INSERT or UPDATE statements either succeed or fail due to constraint violation MySQL has the non standard IGNORE overrides to ignore violations which is not accepted by HyperSQL Unlike MySQL HyperSQL allows you to modify a table with an INSERT UPDATE or DELETE statement which selects from the same table in a subquery Follow the guidelines below for converting MySQL databases and applications Use set database sql syntax MYS statement to enable support for AUTO INCREMENT and TEXT data types These type definitions are translated into HSQLDB equivalents Use MVCC with set database transaction control statement if your application is multi user Avoid storing invalid values for example invalid dates such as 0000 00 00 or 2001 00 00 which are rejected by HyperSQL Avoid the MySQL feature that trims spaces at the end of CHAR values In MySQL a database is the same as a schema In HyperSQL several schemas can exist in the same d
375. inition It is possible to use DECLARE LOCAL TEMPORARY TABLE in a Java method as this is in the session scope There are two ways to use the JDBC Connection object 1 Define the Java method with a Connection parameter as the first parameter This parameter is hidden and only visible to the engine The rest of the parameters if any are used to choose the method according to the required types of parameters 2 Use the SQL JRT Standard jdbc default connection method With this approach the Java method does not include a Connection parameter In the method body the connection is established with a method call to DriverManager as in the example below Connection con DriverManager getConnection jdbc default connection Both methods return a connection that is based on the current session This connection has some extra properties for example the Close method does not actually close it An example of an SQL PROCEDURE with its Java method definition is given below The CREATE PROCEDURE statement is the same with or without the Connection parameter 159 HyperSQL SQL Invoked Routines CREATE PROCEDURE procl IN P1 INT IN P2 INT OUT P3 INT SPECIFIC P2 LANGUAGE JAVA DETERMINISTIC MODIFIES SQL DATA EXTERNAL NAME CLASSPATH org hsqldb test TestStoredProcedure procTest2 In the first example the jdbc default connection method is used In the second example a connection parameter is used pUbIM
376. invoice date must equal one of the holidays in the second example it must be later than all holidays later than the last holiday in the third example it must be on or after some holiday on or after the first holiday and in the fourth example it must be before all holidays before the first holiday invoice_date SOME SELECT holiday_date FROM holidays invoice_date gt ALL SELECT holiday_date FROM holidays invoice_date gt ANY SELECT holiday_date FROM holidays invoice_date lt ALL SELECT holiday_date FROM holidays EXISTS exists predicate lt exists predicate gt EXISTS lt table subquery gt Specify a test for a non empty set If the evaluation of lt table subquery gt results in one or more rows then the expression is TRUE otherwise FALSE UNIQUE unique predicate lt unique predicate gt UNIQUE lt table subquery gt Specify a test for the absence of duplicate rows The result of the test is either TRUE or FALSE never UNKNOWN The rows of the lt table subquery gt that contain one or more NULL values are not considered for this test If the rest of the rows are distinct from each other the result of the test is TRUE otherwise it is FALSE The distinctness of rows X and Y is tested with the predicate X IS DISTINCT FROM Y MATCH match predicate 114 HyperSGL Data Access and Change I match predicate row value predicand MATCH UNIQUE SIMPLE PART
377. ion sql unique_nulls behaviour of multi column UNIQUE constraints with null values This property when set false causes multi column unique constrains to be more restrictive for value sets that contain a mix of null and not null values 232 HyperSGL Properties Name Default Description SET DATABASE SQL UNIQUE NULLS TRUE FALSE Table 12 19 Truncation or Rounding in Type Conversion Name Default Description sql convert trunc behaviour of type conversion from DOUBLE to integral types This property when set false causes type conversions from DOUBLE to any integral type to use rounding By default truncation is used SET DATABASE SQL CONVERT TRUNCATE TRUE FALSE Table 12 20 Decimal Scale of Division and AVG Values Name Default Description sql avg_scale decimal scale of values returned by division and the AVG and MEDIAN aggregate functions By default the result of a division or an AVG or MEDIAN aggregate has the same type and scale as the aggregated value For INTEGER types the scale is 0 When this property is set to a value other than the default 0 then the scale is used if it is greater than the scale of the divisor or aggregated value This property does not affect DOUBLE values Values between 0 10 can be used for this property SET DATABASE SQL AVG SCALE lt numeric value gt Table 12 21 Support for NaN values N
378. ion can be many things Common types include the name of a column in the table expression an expression based on different columns or constant values a function call an aggregate function a CASE WHEN expression Table Expression A table expression is part of the SELECT statement and consists of the FROM clause with optional other clauses that performs selection of rows and grouping from the table s in the FROM clause lt table expression gt lt from clause gt lt where clause gt lt group by clause gt lt having clause gt from clause FROM table reference lt comma gt table reference table reference table primary joined table 121 HyperSGL Data Access and Change table primary table or query name AS correlation name left paren derived column list right paren derived table AS correlation name left paren derived column list right paren lateral derived table AS correlation name left paren derived column list right paren collection derived table AS correlation name left paren derived column list right paren table function derived table AS correlation name left paren derived column list right paren parenthesized joined table AS correlation name left paren derived co
379. ion is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 SQL invoked routines are functions and procedures called from SQL HyperSQL 2 0 supports routines conforming to two parts of the SQL Standard Routines written in the SQL language are supported in conformance to SQL PSM Persistent Stored Modules specification Routines written in Java are supported in broad conformance to SQL JRT specification In addition HyperSQL s previous non standard support for calling Java routines without prior method definition is retained and enhanced in the latest version by extending the SQL JRT specification HyperSQL also supports user defined aggregate functions written in the SQL language or Java This feature is an extension to the SQL Standard SQL invoked routines are schema objects Naming and referencing follows conventions common to all schema objects The same routine name can be defined in two different schemas and used with schema qualified references A routine is either a procedure or a function A function is defined with CREATE FUNCTION always returns a single value or a single table does not modify the data in the database is used as part of an SQL statement can have parameters can be polymorphic A procedure is defined with CREATE PROCEDURE canreturn zero to multiple values or result sets can modify the
380. irectly and there is no grantable privilege that refers to them Statements for Authorization and Access Control The statements listed below allow creation and destruction of USER and ROLE objects The GRANT and REVOKE statements allow roles to be assigned to other roles or to users The same statements are also used in a different form to assign privileges on schema objects to users and roles CREATE USER user definition HyperSQL user definition CREATE USER user name PASSWORD password ADMIN Define a new user and its password user name is an SQL identifier If it is double quoted it is case sensitive otherwise it is turned to uppercase password isa string enclosed with single quote characters and is case sensitive If ADMIN is specified the DBA role is granted to the new user Only a user with the DBA role can execute this statement DROP USER drop user statement HyperSQL drop user statement DROP USER user name Drop destroy an existing user If the specified user is the authorization for a schema the schema is destroyed Only a user with the DBA role can execute this statement ALTER USER SET PASSWORD set the password for a user HyperSQL alter user set password statement ALTER USER user name SET PASSWORD password Change the password of an existing user user name is an SQL identifier If it is double quoted it is case sensitive o
381. is not part of the SQL Standard The strange syntax is due to compatibility with other database engines that support the statement The name is the name of a table view column or routine The name of the column consists of dot separated table name column name The name of the table view or routine can be a simple name All names can be qualified with a schema name If there is already a comment on the object the new comment will replace it The comments appear in the results returned by JDBC DatabaseMetaData methods getTables and getColumns The INFORMATION SCHEMA SYSTEM COMMENTS view contains the comments You can query this view using the schema table and column names to retrieve the comments Schema Creation CREATE SCHEMA schema definition The CREATE SCHEMA or DBA role is required in order to create a schema A schema can be created with or without schema objects Schema objects can always be added after creating the schema or existing ones can be dropped Within the schema definition statement all schema object creation takes place inside the newly created schema Therefore if a schema name is specified for the schema objects the name must match that of the new schema In addition to statements for creating schema objects the statement can include instances of grant statement and role definition This is a curious aspect of the SQL standard as these elements do not really belong to schema creation
382. it type conversion is necessary in two cases One case is to determine the type of a NULL value The other case is to force conversion for special purposes Values of data types can be cast to a character type The exception is BINARY and OTHER types The result of the cast is the literal expression of the value Conversely a value of a character type can be converted to another type if the character value is a literal representation of the value in the target type Special conversions are possible between numeric and interval types which are described in the section covering interval types The examples below show examples of cast with their result CAST NULL AS TIMESTAMP CAST 199 AS INTEGER 199 CAST tRue AS BOOLEAN TRUE CAST INTERVAL 2 DAY AS INTEGER 2 CAST 1992 04 21 AS DATE DATE 1992 04 21 NEXT VALUE FOR 107 HyperSGL Data Access and Change next value expression lt next value expression gt NEXT VALUE FOR lt sequence generator name gt Return the next value of a sequence generator This expression can be used as a select list element in queries or in assignments to table columns in data change statements If the expression is used more than once in a single row that is being evaluated the same value is returned for each invocation After evaluation of the particular row is complete the sequence generator will return a different value from the old value The
383. ition FOR string length USING CHARACTERS OVERLAY binary value expr 1 PLACING binary value expr 2 FROM start position FOR string length The character version of OVERLAY returns a character string based on char value expr 1 inwhich string length characters have been removed from the start position and in their place the whole char value expr 2 is copied The binary version of OVERLAY returns a binary string formed in the same manner as the character version Foundation POSITION POSITION char value expr 1 gt IN char value expr 2 gt USING CHARACTERS POSITION lt binary value expr 1 gt IN lt binary value expr 2 gt The character and binary versions of POSITION search the string value of the second argument for the first occurrence of the first argument string If the search is successful the position in the string is returned as a BIGINT Otherwise zero is returned Foundation RAWTOHEX RAWTOHEX lt binary value expr gt Returns a character string composed of hexadecimal digits representing the bytes in the lt binary value expr gt Each byte of the binary value expr gt is translated into two hex digits HyperSQL REGEXP_MATCHES 175 HyperSQL Built In Functions REGEXP MATCHES char value expr regular expression Returns true if the char value expr gt matches the regular expression asa whole The
384. itten out to the source file by the program the field is enclosed in quote character and any instance of the quote character inside the field is doubled Inserts or updates of CHARACTER type field values are allowed with strings that contains the linefeed or the carriage return character This feature is disabled when both quoted and all quoted properties are false ALTER TABLE commands that add or drop columns or constraints apart from check constraints are not supported with text tables that are connected to a source First use the SET TABLE name SOURCE OFF make the changes then turn the source ON Text File Global Properties The database engine uses a set of defaults for text table properties Each table s data source may override these defaults It is also possible to override the defaults globally so they apply to all text tables The statement SET DATABASE TEXT TABLE DEFAULTS properties string can be used to override the default global properties An example is given below SET DATABASE TEXT TABLE DEFAULTS all quoted true encoding UTF 8 cache rows 10000 cache size 2000 List of supported global properties fs 85 HyperSGL Text Tables e vs e quoted false all quoted false ignore first false encoding ASCII cache rows 1000 cache size 100 e textdb allow full path false a system property Transactions Text tables fully support transactions New or changed rows that have not
385. ivated When an exception occurs the example below performs the UNDO as in the previous example then inserts the invalid data into a separate table 147 HyperSQL SQL Invoked Routines DECLARE UNDO HANDLER FOR SOLEXCEPTION INSERT INTO invalid customers VALUES firstanme lastname address The SOL procedure statement gt is required by the SQL Standard but is optional in HyperSQL If the execution of the lt SQL procedure statement gt specified in the handler declaration throws an exception itself then it is handled by the handlers that are currently active The lt SQL procedure statement gt can itself be a compound statement with its own handlers Assignment Statement The SET statement is used for assignment It can be used flexibly with rows or single values The BNF is given below lt assignment statement gt lt singleton variable assignment gt lt multiple variable assignment gt lt singleton variable assignment gt SET lt assignment target gt lt equals operator gt lt assignment source gt lt multiple variable assignment gt SET lt variable or parameter gt lt row value expression gt In the example below the result of the SELECT is assigned to two OUT or INOUT arguments The SELECT must return one row If it returns more than one an exception is raised If it returns no row no change is made to ARGI and ARG2 SET argl arg2 SELECT coll c
386. ive functions Therefore there is no need to use the fn FUNC NAME escape with HyperSQL If a JDBC function is supported by the SQL Standard in a different form the SQL Standard form is the preferred form to use HyperSQL Built In Functions Many additional built in functions are available for some useful operations Some of these functions return the current setting for the session and the database The General Functions accept arguments of different types and return values based on comparison between the arguments In the BNF specification used here words in capital letters are actual tokens Syntactic elements such as expressions are enclosed in angle brackets The left paren and right paren tokens are represented with the actual symbol Optional elements are enclosed with square brackets left bracket gt and right bracket gt Multiple options for a required element are enclosed with braces left brace and right brace Alternative tokens are separated with the vertical bar vertical bar At the end of each function definition 172 HyperSQL Built In Functions the standard which specifies the function is noted in parentheses as JDBC or HyperSQL or the SQL Foundation part of the SQL Standard String and Binary String Functions In SQL there are three kinds of string character binary and bit The units are respectively characters octets and bits Each kind of string can be
387. ize it when it s not in use Invoking a Gradle Build from the Command Line You can invoke graphical and non graphical Gradle builds from the command line 1 Get a command line shell Windows users can use either Start Run or Start Start Search and enter cmd Non windows users will know how to get a shell 2 In the shell cd to the build directory under the root directory where you extracted or installed HyperSQL to Operating system search or find functions can be used if you can t find it quickly by poking around on the command line or with Windows Explorer etc 3 Windows users can ignore this step UNIX shell users should ensure that the current directory is in their search path or prefix their gradlew or gradle gui command in the next step with e g like gradlew 285 HyperSGL Building HyperSQL Jars 4 Inthe shell run either gradle gui for a graphical build or gradlew for a text based build The gradle gui file is our own wrapper script for gradlew gui Be aware that both gradle gui and gradlew gui suffer from the limitation that the gui switch is mutually exclusive with most or all other arguments including tasks I have registered GRADLE bugs 1861 and 1863 about this Using Gradle Using Text based Gradle If you ran just gradlew or gradlew bat then you will be presented with simple instructions for how to do everything that you want to do Basically you will run the same gradlew
388. ize n For certain applications such as real time systems this allows asynchronous notifications to be sent by the trigger event without introducing delays in the engine With asynchronous triggers an extra parameter NOWAIT can be used in trigger definition This overcomes the queue full condition In this mode old calls that are still in the queue are discarded one by one and replaced with new calls Java row level triggers that are declared with BEFORE trigger action time can modify the row data Triggers with AFTER trigger action time can modify the database e g insert new rows If the trigger needs to access the database the same method as in Java Language Routines SQL JRT can be used The Java code should connect to the URL jdbc default connection and use this connection to access the database For sample trigger classes and test code see org hsqldb sample TriggerSample org hsqldb test TestTriggers org hsqldb test TriggerClass and the associated text script TestTriggers txt inthe testrun hsqldb directory In the example below the trigger is activated only if the update statement includes SET clauses that modify any of the specified columns cl c2 c3 Furthermore the trigger is not activated if the c2 column in the updated row is null CREATE TRIGGER TRIGBUR BEFORE UPDATE OF ci c2 c3 ON testtrig referencing NEW ROW AS newrow FOR EACH ROW WHEN newrow c2 IS NOT NULL CALL org hsqldb test TriggerClass Java functions
389. ke HSQLDB can perform millions of read and write operations in an hour As system hardware and software can go wrong it is impossible to achieve zero failure rate Therefore regular backups are recommended HyperSQL 2 2 has built in database backup and restore features discussed elsewhere in this chapter A note regarding the NIO file access implementation This implementation applies only to CACHED table data in the data file Other files are not accessed via NIO There has been an issue with some JVM implementations of nio not releasing the file buffers after they were closed HyperSQL uses a workaround which is recommended for Sun JVM s This does not apply to other JVM s In such environments it is therefore recommended to test the CHECKPOINT DEFRAG operation and the shutting down and restarting the database inside the same Java process extensively with NIO Use of NIO can be turned off if necessary Atomicity Consistency Isolation Durability Atomicity means a transaction either fails without changing the data or succeeds HyperSQL ensures atomicity both during operations and in the event of a system crash Consistency means all the implicit and explicit integrity constraints are always enforced HyperSQL always enforces the constraints and at the same time does not allow unenforceable constraints illegal forms of CHECK constraints to be created Isolation means transactions do not interfere with each other HyperSQL enforces isolation
390. keywords cannot be used as HyperSQL identifiers The keywords are as follows ALL AND ANY AS AT AVG BETWEEN BOTH BY CALL CASE CAST COALESCE CORRESPONDING CONVERT COUNT CREATE CROSS DEFAULT DISTINCT DROP ELSE END EVERY EXISTS EXCEPT FOR FROM FULL GRANT GROUP HAVING 280 HyperSGL Lists of Keywords IN INNER INTERSECT INTO IS JOIN LEFT LEADING LIKE MAX MIN NATURAL NOT NULLIF ON ORDER OR OUTER PRIMARY REFERENCES RIGHT SELECT SET SOME STDDEV POP STDDEV SAMP SUM TABLE THEN TO TRAILING TRIGGER UNION UNIQUE USING VALUES VAR POP VAR SAMP WHEN WHERE WITH Special Function Keywords HyperSQL supports SQL Standard functions that are called without parentheses These functions include CURRENT DATE LOCALTIMESTAMP TIMEZONE HOUR USER etc When the default SET DATABASE SQL NAMES FALSE mode is used keywords that are names of SQL functions can be used as column names without double quotes in CREATE TABLE statements But when the identifier is a column name and is referenced in SELECT or other statements the keywords must be double quoted Otherwise the result of the SQL function is returned instead of the column value HyperSQL also supports non standard functions SYSTIMESTAMP CURDATE CURTIME TODAY SYSDATE and NOW which can be called with or without parentheses e g NOW or NOW
391. ko on e a ha ee ptet kosa yen batis 147 Assignment Statement 25 eoo ei desin petuo Eo sisse ee eke PL er Dem Da ee ee Pap P Ur ni dee Y 148 Select Statement Single ROW 1 oec eiie scorsi eee ehesesteme se eet odba exeo sizan pletri etik de rin ee es 148 Formal P r eters Re 148 t rated State MENAS dedi a nt a ey nn ev net cannons Se fel meu ric pen e kanpe e ke i 149 Tterated FOR Statement vicis cc iv ie csecdh vii sot ke dine a ole a ai ka ina po ks l de TN kk ER RI RE SAY Se kl ER 150 Conditional Statements sic ovweccassevecucsisnedanneseapnceesvhuusarey vi is OT bd kak ie ede AA pe ETUR ERU ae 150 Return Statement siirde E i Tin REEE EEEE paka k SEE reve RR E C RA e ke bo bere 152 Control Statements secre set dote abone fy is nbsp rin E E demake TE UE den 152 Raising EXCEptIONS avi Ye p X mT 153 Routine Polymorphisti i5 akssastasniytm es se ek pose nins quae Eos enilkss ses ea dedike panou aiei ota 153 Returning Data From Procedures He e mee hee rennen 154 Recursive ROUUDES Me Pn n RS A G gn 155 Java Language Routines SQL JRT esses ee me he mee hene men nennen meer serene eene 156 PolymOTPAISON soti M 157 Java Language Procedures eese eese eee tae the tnn ee teeth ne st desevosmassyooesosknvons 158 EVERETT 159 Legacy Support o nee p
392. l than requested by the application HyperSQL promotes a READ UNCOMMITTED request to READ COMMITTED and promotes a REPEATABLE READ request to SERIALIZABLE The MVCC model is not covered directly by the Standard Research has established that the READ CONSISTENCY level fulfils the requirements of and is stronger than the READ COMMITTED level The SNAPSHOT ISOLATION level is stronger than the READ CONSISTENCY level It avoids the three anomalies defined by the Standard and is therefore stronger than the REPEATABLE READ level as defined by the Standard When operating with the MVCC model HyperSQL treats a REPEATABLE READ or SERIALIZABLE setting for a transaction as SNAPSHOT ISOLATION All modes can be used with as many simultaneous connections as required The default 2PL model is fine for applications with a single connection or applications that do not access the same tables heavily for writes With multiple simultaneous connections MVCC can be used for most applications Both READ CONSISTENCY and 34 HyperSGL Sessions and Transactions SNAPSHOT ISOLATION levels are stronger than the corresponding READ COMMITTED level in the 2PL mode Some applications require SERIALIZABLE transactions for at least some of their operations For these applications one of the 2PL modes can be used It is possible to switch the concurrency model while the database is operational Therefore the model can be changed for the duration of some special operations
393. lable for the specified value nio is not used Server Databases Running databases in a HyperSQL server is the best overall method of access As the JVM process is separate from the application this method is the most reliable as well as the most accessible method of running databases Upgrading Databases Any database that is not produced with the release version of HyperSQL 2 0 must be upgraded to this version 271 HyperSGL Deployment Guide Procedure 15 1 Upgrading Databases Created with Version 1 8 x 1 Open the database with the jar that created it and perform the SHUTDOWN statement as an SQL statement 2 Open the database with the HyperSQL 2 0 jar 3 Perform the SHUTDOWN COMPACT statement The first step is to guarantee there is no log file for the database When upgrading an application that has been deployed on a large scale it is sometimes not practical to perform the first step of this procedure with the old jar You can ignore the first step but you may lose part of the database statements that are stored in the log file Therefore you need to test with databases created with your application to make sure typical statements that are logged in the log file are compatible with the new version Examples of known incompatible statements are some DDL statements used for changing the data type or default values of column A note about SHUTDOWN modes SHUTDOWN COMPACT is equivalent to SHUTDOWN SCRIPT plus opening
394. lation name drop behavior Destroy a collation If the drop behavior is CASCADE then all references to the collation revert to the default collation that would be in force if the dropped collation was not specified 72 HyperSGL Schemas and Database Objects CREATE TRANSLATION transliteration definition transliteration definition CREATE TRANSLATION transliteration name FOR source character set specification TO target character set specification FROM transliteration source source character set specification character set specification target character set specification character set specification transliteration source existing transliteration name gt transliteration routine existing transliteration name transliteration name gt transliteration routine specific routine designator gt Define a character transliteration This feature may be supported in a future versions of HyperSQL DROP TRANSLATION drop transliteration statement drop transliteration statement DROP TRANSLATION transliteration name Destroy a character transliteration This feature may be supported in a future versions of HyperSQL CREATE ASSERTION assertion definition assertion definition CREATE ASSERTION constraint name CHECK left paren search condition right paren constraint characteristics Spec
395. le 1 0 milestone 3 Wrapping Ant 1 8 2 To run a build run gradle task To see a list of available tasks run gradle tasks Add switch q to make Gradle run quieter or i s to run louder or d S for very loud Sample Gradle GUI Screen Procedure B 3 First Time using Gradle Gui It takes the Gradle gui a while to start up because similar to an IDE it is generating a list of details about available tasks 2 Inthe main window in the top panel with the Task Tree tab selected you have the list of public tasks sorted alphabetically Down bottom is displayed the output of the last task s execution After startup it will show the output of the task tasks 287 HyperSGL Building HyperSQL Jars 3 Scroll to the help task and click it once to select it then click the green Execute toolbar button above You could also have double clicked the item but you can use the selection procedure to pick multiple tasks with Control or Shift keys to execute multiple tasks in a single run and the tasks will execute in the same order that you had selected them 4 Scroll through and read the output of the help task in the bottom panel Where this help screen speaks about verbosity switches you can accomplish the same thing by using the Setup tab Whenever Gradle output in the bottom panel talks about running gradlew sometask you can execute the specified task s by selecting and executing them like we just
396. les that are used inside the Java method User Defined Aggregate Functions HyperSQL adds an extension to the SQL Standard to allow user defined aggregate functions A user defined aggregate function has a single parameter when it is used in SQL statements Unlike the predefined aggregate functions the keyword DISTINCT cannot be used when a user defined aggregate function is invoked Like all user defined functions an aggregate function belongs to a schema and can be polymorphic using multiple function definitions with the same name but different parameter types A user defined aggregate function can be used in SQL statements where a predefined aggregate function is allowed Definition of Aggregate Functions An aggregate function is always defined with 4 parameters The first parameter is the parameter that is used when the function is invoked in SQL statements the rest of the parameter are invisible to the invoking SQL statement The type of the first parameter is user defined The type of the second parameter must be BOOLEAN The third and fourth parameters have user defined types and must be defined as INOUT parameters The defined return type of the function determines the type of the value returned when the function is invoked CREATE AGGREGATE FUNCTION user defined aggregate function definition Aggregate function definition is similar to normal function definition and has the mandatory lt returns clause gt The BNF is given below
397. lication server such as Tomcat or Resin provides access to the database The Servlet Mode cannot be started independently from the servlet engine The Servlet class in the HSQLDB jar should be installed on the application server to provide the connection The database is specified using an application server property Refer to the source file src org hsqldb server Servlet java to see the details Both HTTP Server and Servlet modes can only be accessed using the JDBC driver at the client end They do not provide a web front end to the database The Servlet mode can serve only a single database Please note that you do not normally use this mode if you are using the database engine in an application server In this situation connections to a catalog are usually made in process or using an external HSQL Server instance Server and Web Server Properties Properties files for running the servers are not created automatically You should create your own files that contain server property value pairs for each property The server properties or webserver properties files must be located in the directory where the command to run the org hsqldb server Server class is issued In all properties files values are case sensitive All values apart from names of files or pages are required in lowercase e g server silentZFALSE will have no effect but server silent false will work Supported properties and their default values if any are as follows
398. lick on Program in the left navigator Right click Project in the left navigator panel and select New Depending on the state of your workspace instead of New in the context sensitive menu there may be a New configuration or similar item nested under Program in which case you should select that 3 To the right change the value in the Name field to HSOLDB Gradle or whatever name you want for this launcher config this Gradle launcher is only for your HSQLDB project 4 Make sure that the Main tab is selected 5 For the Location field use the Browse Workspace button to navigate to and select the gradle gui cmd Windows or gradle gui other file in the build directory of your HyperSQL project 283 HyperSQL Building HyperSQL Jars Sw External Tools Configurations W wy Y Create manage and run configurations Run a program L L Hg AT Name HSQLDB Gradle Ej Main y Refresh oi Build P Environment 1 Common rLocation amp blenderjme build workspace_loc hsqldb 16 build gradle gui hsqldb 1 4 build j Browse File system Variables 3 hsqldb 1 4 build hsqldb 16 build X Working Directory v Q Program gt New confi ratic ane ese Browse Workspace Browse File System Variables Arguments v X Ant Build Variable rc Note Enclose an argument containing spaces using double quote
399. limited value specification value specification lt value specification gt lt literal gt lt general value specification gt unsigned value specification gt unsigned literal general value specification gt lt target specification gt lt host parameter specification gt lt SQL parameter reference gt lt column reference gt lt dynamic parameter specification gt simple target specification host parameter specification SQL parameter reference column reference embedded variable name host parameter specification host parameter name indicator parameter dynamic parameter specification question mark Specify one or more values host parameters SOL parameters dynamic parameters or host variables row value expression row value expression row value expression row value special case explicit row value constructor row value predicand row value special case row value constructor predicand gt lt row value special case gt lt nonparenthesized value expression primary gt lt explicit row value constructor gt lt left paren gt lt row value constructor element gt lt comma gt lt row value constructor element list gt lt right paren gt ROW left paren lt row value constructor element list right paren lt row subquery gt Specify a row consisting of one or more elements
400. ller than 1 or equal values for lt value expr 2 gt and lt value expr 3 will cause an exception Foundation An example is given below WIDTHSBUCKE TN S T 1 0 0r 10 0 WiIDTHEBUCKE 237 OPES 2 WIDTH BUCKET 100 10 110 10 10 WIDTHS BUCKET 200 10 110 10 1 Date Time and Interval Functions Functions to report the time zone Functions to Report the Time Zone TIMEZONE TIMI EZONI E Returns the current time zone for the session Returns an INTERVAL HOUR TO MINUTE value HyperSQL SESSION_TIMEZONE SESSION TIMI EZONI E Returns the default time zone for the current session Returns an INTERVAL HOUR TO MINUTE value HyperSQL DATABASE_TIMEZONE DATABASI IM EZONI E T E 182 HyperSGL Built In Functions Returns the time zone for the database engine This is based on where the database server process is located Returns an INTERVAL HOUR TO MINUTE value HyperSQL Functions to Report the Current Datetime CURRENT DATE CURRENT DATE CURRENT TIME CURRENT TIME time precision LOCALTIME LOCALTIME time precision CURRENT TIMESTAMP CURRENT TIMESTAMP timestamp precision LOCALTIMESTAMP LOCALTIMESTAMP timestamp precision These datetime functions return the datetime value representing the moment the function is called CURRENT
401. low syntax and type names that are supported by some popular RDBMS User defined types and functions including aggregate functions allow any type or function that is supported by some RDBMS to be defined and used In the future the supported compatibility modes with other RDBMS will be expanded further PostgreSQL Compatibility PostgreSQL is fairly compatible with the Standard but uses some non standard features e Use set database sql syntax PGS statement to enable the PostgreSQL s non standard features References to SERIAL BIGSERIAL and TEXT data types as well as sequence functions are translated into HSQLDB equivalents Use MVCC if your application is multi user PostgreSQL functions are generally supported For identity columns PostgreSQL uses a non standard linkage with an external identity sequence In most cases this can be converted to GENERATED BY DEFAULT AS IDENTITY Inthose cases where the identity sequence needs to be shared by multiple tables you can use a new HyperSQL 2 2 feature GENERATED BY DEFAULT AS SEQUENCE sequence name which is the equivalent of the PostgreSQL implementation In CREATE TABLE statements the SERIAL and BIGSERIAL types are translated into INTEGER or BIGINT with GENERATED BY DEFAULT AS IDENTITY Usage of DEFAULT NEXTVAL lt sequence name is supported so long as the sequence name refers to an existing sequence This usage is translated into GENER
402. lue TRUE FALSE UNKNOWN Xboolean primary predicate boolean predicand boolean predicand HE parenthesized boolean value expression nonparenthesized value expression primary 110 HyperSGL Data Access and Change Xparenthesized boolean value expression left paren boolean value expression right paren Specify a boolean value Predicates Predicates are conditions with two sides and evaluate to a boolean value The left side of the predicate the row value predicand is the common element of all predicates This element is a generalisation of both value expression which is a scalar and of explicit row value constructor which is a row The two sides of a predicate can be split in CASE statements where the row value predicand is part of multiple predicates The number of fields in all row value predicand used in predicates must be the same and the types of the fields in the same position must be compatible for comparison If either of these conditions does not hold an exception is raised The number of fields in a row is called the degree In many types of predicates but not all of them if the row value predicand gt evaluates to NULL the result of the predicate is UNKNOWN If the row value predicand gt has more than one element and one or more of the fields evaluate to NULL the result depends on the particular predicate comparison predicand compa
403. lue in the range of 1 31 JDBC DAYOFWEEK DAYOFWEEK datetime valu xpr gt This function is equivalent to EXTRACT DAY OF WEEK FROM Returns an integer value in the range of 1 7 The first day of the week is Sunday JDBC DAYOFYEAR DAYOFYEAR datetime valu xpr gt This function is equivalent to EXTRACT DAY OF YEAR FROM Returns an integer value in the range of 1 366 JDBC DAYS DAYS datetime valu xpr gt The datetime valu xpr isof DATE or TIMESTAMP type This function returns the DAY number since the first day of the calendar The first day is numbered 1 HyperSQL HOUR HOUR datetime valu xpr gt This function is equivalent to EXTRACT HOUR FROM Returns an integer value in the range of 0 23 JDBC MINUTE MINUTE datetime valu xpr gt 184 HyperSGL Built In Functions This function is equivalent to EXTRACT MINUTE FROM Returns an integer value in the range of 0 59 JDBC MONTH MONTH datetime valu xpr gt This function is equivalent to EXTRACT MONTH FROM Returns an integer value in the range of 1 12 JDBC MONTHNAME MONTHNAME datetime valu xpr gt This function is equivalent to EXTRACT NAME OF MONTH FROM Returns a string in the range of January December JDBC QUARTER QUARTER datetime valu xpr gt This functi
404. lue of a column can be autogenerated in two ways One way is specific to columns of integral types INTEGER BIGINT etc and associates a sequence generator with the column When a new row is inserted into the table the value of the column is generated as the next available value in the sequence The SQL Standard supports the use of unnamed sequences with the IDENTITY keyword In addition HyperSQL supports the use of a named SEQUENCE object which must be in the same schema as the table identity column specification GENERATED ALWAYS BY DEFAULT AS IDENTITY left paren common sequence generator options right paren identity column sequence specification GENERATED BY DEFAULT AS SEQUENCE sequence name gt The lt identity column specification or identity column sequence specification can be specified for only a single column of the table The identity column specification is used for columns which represent values based on an unnamed sequence generator It is possible to insert a row into the table without specifying a value for the column The value is then generated by the sequence generators according to its rules An identity column may or may not be the primary key Example below CREATE TABLE t id INTEGER GENERATED ALWAYS AS IDENTITY START WITH 100 name VARCHAR 20 PRIMARY KEY The identity column sequence specification is u
405. lumn list right paren lt where clause gt WHERE lt boolean value expression gt lt group by clause gt GROUP BY lt set quantifier gt lt grouping element gt lt comma gt grouping element having clause HAVING boolean value expression The from clause contains one or more table reference separated by commas A table reference is often a table or view name or a joined table The where clause filters the rows of the table in the from clause and removes the rows for which the search condition is not TRUE The group by clause isacomma separated list of columns of the table in the from clause orexpressions based on the columns When a group by clause is used only the columns used in the group by clause or expressions used there can be used in the select list gt together with any aggregate function on other columns A group by clause compares the rows and groups together the rows that have the same values in the columns of the group by clause Then any aggregate function inthe select list is performed on each group and for each group a row is formed that contains the values of the columns of the group by clause and the values returned from each aggregate function In the first example below a simple column reference is used in GROUP BY while in the second example an expression is used RV MTABBESaEable fa INT SD
406. ly The SELECT statement must return exactly one row In this example the SELECT statement refers to the existing value for column C in its search condition UPDATE T SET A 5 WHERE UPDATE T SET A B 1 NULL WHERE UPDATE T SET A C SELECT X Y FROM U WHERE Z C B 10 WHERE UPDATE T SET A 3 B 3 warm Merge Statement MERGE INTO merge statement merge statement MERGE INTO target table AS merge correlation name USING table reference ON search condition merge operation Specification merge correlation name correlation name merge operation specification merge when clause merge when clause merge when matched clause merge when not matched clause merge when matched clause WHEN MATCHED THEN merge update specification merge when not matched clause WHEN NOT MATCHED THEN merge insert Specification merge update specification UPDATE SET set clause list merge insert specification INSERT left paren insert column list right paren override clause VALUES merge insert value list merge insert value list left paren merge insert value element comma merge insert value element right paren merge insert value element value expression contextually typed val
407. ly The default write delay of 0 5 second is fine for many applications You can also use the property hsqldb write_delay_millis 100 to reduce it to 0 1 second or the property hsqldb write_delay false to forcea disk sync after each commit Before the application is closed you should perform the SHUTDOWN command to ensure the database is opened instantly when it is next opened Note you don t need to use SHUTDOWN COMPACT as routine Embedded Databases in Server Applications This usage involves a server application such as a web application connecting to an embedded HyperSQL instance In this usage the database is often accessed heavily therefore performance and latency is a consideration If the database is updated heavily the default value of the WRITE DELAY property 0 5 sec is often enough as it is assumed the server or the application does not go down frequently If it is necessary you can reduce the WRITE DELAY to a small value 20 ms without impacting the update speed If you reduce WRITE DELAY to zero performance drops to the speed of disk file sync operation Alternatively a server application can use an all in mem database instance for fast access while sending the data changes to a persistent disk based instance either periodically or in real time Mixed Mode Embedding a HyperSQL Server Listener Since you won t be able to access in process database instances from other processes you will often want to run a Liste
408. ly new to the Standard several database products used other types to represent boolean values For improved compatibility HyperSQL allows some type conversions to boolean Values of BIT and BIT VARYING types with length 1 can be converted to BOOLEAN If the bit is set the result of conversion is the TRUE value otherwise it is FALSE 13 HyperSGL SQL Language Values of TINYINT SMALLINT INTEGER and BIGINT types can be converted to BOOLEAN If the value is zero the result is the FALSE value otherwise it is TRUE Character String Types The CHARACTER CHARACTER VARYING and CLOB types are the SQL Standard character string types CHAR VARCHAR and CHARACTER LARGE OBJECT are synonyms for these types HyperSQL also supports LONGVARCHAR as a synonym for VARCHAR If LONGVARCHAR is used without a length then a length of 16M is assigned You can set LONGVARCHAR to map to CLOB with the sql longvar is lob connection property or the SET DATABASE SQL LONGVAR IS LOB TRUE statement HyperSQL s default character set is Unicode therefore all possible character strings can be represented by these types The SQL Standard behaviour of the CHARACTER type is a remnant of legacy systems in which character strings are padded with spaces to fill a fixed width These spaces are sometimes significant while in other cases they are silently discarded It would be best to avoid the CHARACTER type altogether With the rest of the types the strings are not pad
409. me Zone 17 TIMEZONE function 182 TO CHAR function 188 TO DATE function 189 TO NUMBER function 181 TO TIMESTAMP function 189 TODAY function 184 TRANSACTION CONTROL function 196 306 HyperSGL General Index TRANSACTION ID function 196 TRANSACTION SIZE function 196 transaction characteristics 36 TRANSLATIONS 78 TRIGGER COLUMN USAGE 79 TRIGGER ROUTINE USAGE 79 TRIGGER SEQUENCE USAGE 79 TRIGGER TABLE USAGE 79 TRIGGERED UPDATE COLUMNS 78 TRIGGERED SQL STATEMENT 170 TRIGGER EXECUTION ORDER 170 TRIGGERS 79 TRIM ARRAY function 190 TRIM function 177 TRUNCATE function 181 TRUNCATE SCHEMA 132 TRUNCATE TABLE 132 TRUNC function datetime 188 TRUNC function numeric 181 U UCASE function 177 unicode escape elements 100 UNION JOIN 125 UNIQUE constraint 56 UNIQUE predicate 114 UNIX TIMESTAMP function 185 UNNEST 123 UPDATE 134 upgrading 271 UPPER function 178 USAGE PRIVILEGES 79 USER DEFINED TYPES 79 USER function 194 UUID function 193 V value expression 108 value expression primary 104 value specification 105 VIEW COLUMN USAGE 79 VIEW ROUTINE USAGE 79 VIEW TABLE USAGE 79 VIEWS 79 W WEEK function 185 WHILE loop in routines 149 WIDTH BUCKET function 182 Y YEAR function 185 307
410. me of xdb The public name hides the file names from users java cp lib hsqldb jar org hsqldb server Server database 0 file mydb dbname 0 xdb The command line argument help can be used to get a list of available arguments HyperSQL HTTP Server This method of access is used when the computer hosting the database server is restricted to the HTTP protocol The only reason for using this method of access is restrictions imposed by firewalls on the client or server machines and it should not be used where there are no such restrictions The HyperSQL HTTP Server is a special web server that allows JDBC clients to connect via HTTP The server can also act as a small general purpose web server for static pages To run an HTTP server replace the main class for the server in the example command line above with the following org hsqldb server WebServer The command line argument help can be used to get a list of available arguments HyperSQL HTTP Servlet This method of access also uses the HTTP protocol It is used when a separate servlet engine or application server such as Tomcat or Resin provides access to the database The Servlet Mode cannot be started independently from the servlet engine The Servlet class in the HSQLDB jar should be installed on the application server to provide the connection The database is specified using an application server property Refer to the source file src org hsqldb s
411. me that you run your client program For example Example 13 3 Specifying your own trust store to a JDBC client java Djavax net ssl trustStore home blaine trust store jar path to hsqldb jar dest urlid This example runs the program SqITool SqlTool has built in TLS support however so for SqlTool you can set truststore on a per urlid basis in the SqlTool configuration file Note The hostname in your database URL must match the Common Name of the server s certificate exactly That means that if a site certificate is admc com you can not use jdbc hsqldb hsqls localhost or jdbc hsqldb hsqls www admc com 1100 to connect to it If you want more details on anything see JSSERefGuide html on Sun s site http java sun com javase 6 docs technotes guides security jsse JSSERefGuide html or in the subdirectory docs guide security jsse of your Java SE docs Server Side Listener Side Get yourself a JKS keystore containing a private key Then set properties server tls System javax net ssl keyStore and system javax net ssl keyStorePassword in your 248 HyperSGL HyperSQL Network Listeners Servers server properties or webserver properties file Set server tls to true system javax net ssl keyStore to the path of the private key JKS keystore and system javax net ssl keyStorePassword to the password of both the keystore and the private key record they must be the same If you specify relative file path v
412. ment SQL session statement SQL diagnostics statement SQL dynamic Statement SQL schema statement SQL schema definition statement SQL schema manipulation statement SOL schema definition statement schema definition table definition view definition SQL invoked routine grant statement role definition domain definition character set definition collation definition transliteration definition assertion definition trigger definition user defined type definition user defined cast definition user defined ordering definition transform definition sequence generator definition SQL schema manipulation statement drop schema statement alter table Statement drop table statement drop view statement alter routine statement drop routine statement drop user defined cast statement revoke statement drop role statement alter domain statement drop domain statement drop character set statement drop collation statement drop transliteration statement drop assertion statement drop trigger statement alter type statement drop data type statement alter sequence generator statement drop sequence generator statement Other Schema Object Creation CREATE INDEX 70 HyperSGL Schemas and Databa
413. mes to these rows so that the rows can be referenced in the trigger action In the example below a name is given to the NEW ROW and it is used both in the WHEN clause and in the trigger action SQL to insert a row into a triglog table after each row insert into the testtrig table CREATE TRIGGER trig AFTER INSERT ON testtrig REFERENCING NEW ROW AS newrow FOR EACH ROW WHEN newrow id 1 INSERT INTO TRIGLOG VALUES newrow id newrow data inserted In the example blow the trigger code modifies the updated data if a condition is true This type of trigger is useful when the application does not perform the necessary checks and modifications to data The statement block that starts with BEGIN ATOMIC is similar to an SOL PSM block and can contain all the SQL statements that are allowed in an SQL PSM block CREATE TRIGGER t BEFORE UPDATE ON customer REFERENCING NEW AS newrow FOR EACH ROW BEGIN ATOMIC IF LENGTH newrow firstname 10 THEN SET newrow firstname LOWER newrow firstname 167 HyperSGL Triggers END IF END Trigger Action in Java A trigger action can be written as a Java class that implements the org hsqldb Trigger interface This interface has a single method which is called when the trigger is activated either before or after the event When the method is called by the engine it supplies the type of trigger as an int value defined by the interface as type argument the name of the trigger
414. mon aggregate functions return the maximum minimum and average value among the values in different TOWS Set Operations Set and Multiset Operations While join operations generally result in laterally expanded tables SET and COLLECTION operations are performed on two tables that have the same degree and result in a table of the same degree The SET operations are UNION INTERSECT and EXCEPT difference When each of these operations is performed on two tables the collection of rows in each table and in the result is reduced to a set of rows by eliminating duplicates The set operations are then performed on the two tables resulting in the new table which itself is a set of rows Collection operations are similar but the tables are not reduced to sets before or after the operation and the result is not necessarily a set but a collection of rows The set operations on two tables A and B are A UNION DISTINCT B A INTERSECT DISTINCT BandA EXCEPT DISTINCT B The result table is formed in the following way The UNION operation adds all the rows from A and B into the new table but avoids copying duplicate rows The INTERSECT operation copies only those rows from each table that also exist in the other table but avoids copying duplicate rows The EXCEPT operation copies those rows from the first table which do not exist in the second table but avoids copying duplicate rows The collection operations are similar to the set ope
415. mple Snapshot Gradle Dependency sess emere rennen 276 15 7 Sample Snapshot ivy xml loaded by Ivyxml plugin eese HH 276 15 8 Sample Snapshot Groovy Dependency using Grape ssssssesse e emere 276 15 9 Sample Range Ivy Dependency i22 eee teet tree ile b rhe e eo ER aj PERO l ki be t tK aji ke ba Ed 277 15 10 Sample Range Maven Dependency visc dcccsen dn tese dte dee too bek re tease weds duds im ae pd pe mm kwe bikini d 277 15 11 Sample Range Gradle Dependency eerte rete tener hehe Rp hg ebore anke o pese e ERR EEEE np 277 15 12 Sample Range ivy xml loaded by Ivyxml plugin 2000 0 sese HH 277 15 13 Sample Range Groovy Dependency using Grape sesssssse eene 278 B 1 Buiding the standard Hsqldb jar file with Ant em emen 289 B 2 Example source code before CodeSwitcher is run ssessssseeeee e ee eene 290 B 3 CodeSwitcher command line invocation ssssssssse eme meme men rennen 290 B 4 Source code after CodeSwitcher processing ssessesseseee e eem ene hee hee ener enneee 290 HyperSQL Preface HSQLDB HyperSQL DataBase is a modern relational database manager that conforms closely to the SQL 2008 Standard and JDBC 4 specifications It supports all core features and many of the optional features of SQL 2008 The first versions of HSQLDB were released in 2001 Version 2 0 first released in 2010 includes a complete rewrit
416. n nullif expression NULLIF left paren value expression comma value expression right paren Return NULL if two values are equal If the result of the first lt value expression is not equal to the result of the second then it is returned otherwise NULL is returned The type of the return value is the type of the first value expression SELECT i NULLIF n not defined FROM t CASE case specification case specification simple case searched case simple case CASE case operand simple when clause else clause END searched case CASE searched when clause else clause END simple when clause WHEN when operand list THEN result searched when clause WHEN search condition THEN result else clause ELSE result 106 HyperSGL Data Access and Change case operand row value predicand gt overlaps predicate part l when operand list when operand comma when operand when operand row value predicand comparison predicate part 2 between predicate part 2 in predicate part 2 character like predicat part 2 octet like predicate part 2 similar predicate part 2 regex like predicate part 2 null predicate part 2 quantified comparison predicate part 2
417. n OLD state For INSERT triggers there is only the NEW state If a trigger is FOR EACH STATEMENT then a transient table is created containing all the rows for the OLD state and another transient table is created for the NEW state 169 HyperSGL Triggers The REFERENCING transition table or variable isusedto give a name to the OLD and NEW data row or table This name can be referenced in the SQL procedure statement to access the data The optional triggered when clause isa search condition similar to the search condition of a DELETE or UPDATE statement If the search condition is not TRUE for a row then the trigger is not activated for that row The SQL procedure statement is limited to INSERT DELETE UPDATE and MERGE statements The HSQLDB trigger class FON is a delimited identifier that contains the fully qualified name of a Java class that implements the org hsqldb Trigger interface Early releases of HyperSQL version 2 0 do not allow the use of OLD TABLE or NEW TABLE in statement level triggers TRIGGERED SQL STATEMENT triggered SQL statement The triggered SQL statement has three forms The first form is a single SQL procedure statement This statement can reference the OLD ROW and NEW ROW variables For example it can reference these variables and insert a row into a separate table The second form is enclosed in a BEGIN END block and can include one or more SQL proce
418. n all the table in the schema If the additional NO CHECK option is also specified then the TRUNCATE statement is executed even if any of the tables in the schema is referenced in a FOREIGN KEY constraint defined on a non empty table in a different schema 132 HyperSGL Data Access and Change If RESTART IDENTITY is specified all table IDENTITY sequences and all SEQUENCE objects in the schema are reset to their start values Use of this statement requires schema ownership or administrative privileges Insert Statement INSERT INTO insert statement insert statement INSERT INTO target table insert columns and source insert columns and source from subquery from constructor from default from subquery left paren insert column list right paren override clause query expression from constructor gt left paren insert column list right paren override clause contextually typed table value constructor override clause OVERRIDING USER VALUE OVERRIDING SYSTEM VALUE from default gt DEFAULT VALUES lt insert column list gt lt column name list gt Insert new rows in a table An INSERT statement inserts one or more rows into the table The special form INSERT INTO lt target table gt DEFAULT VALUES can be used with tables which have a default value for each column
419. n an ORDER BY clause if all the columns in ORDER BY are in a single column or multi column index in the exact order This is important if there is a LIMIT n or FETCH n ROWS ONLY clause In this situation the use of index allows the query processor to access only the number of rows specified in the LIMIT clause instead of building the whole result set which can be huge This also works for joined tables when the ORDER BY clause is on the columns of the first table in a join Indexes are used in the same way when ORDER BY DESC is specified in the query Note that unlike some other RDBMS HyperSQL does not need or create DESC indexes It can use any ordinary ascending index for ORDER BY DESC If there is an equality or range condition e g EQUALS GREATER THAN condition on the columns specified in the ORDER BY clause the index is still used In the two examples below the index on TA COL3 is used and only up to 1000 rows are processed and returned TA is a very large table with an index on TA COL3 SELECT FROM TA JOIN TB ON TA COL2 TB COL1 WHERE TA COL3 gt 40000 ORDER BY TA COL3 LIMIT 1000 28 HyperSGL SQL Language SELECT FROM TA JOIN TB ON TA COL2 TB COL1 WHERE TA COL3 40000 AND TA COL3 100000 ORDER BY TA COL3 DESC LIMIT 1000 But if the query contains an equality condition on another indexed column in the table this may take precedence and no index may be used for ORDER BY In this case USING I
420. n is raised if there is no ELSE clause and no search condition evaluates TRUE if statement gt IF search condition if statement then clause if statement elseif clause if statement else clause END IF if statement then clause THEN SQL statement list lt if statement elseif clause ELSEIF search condition THEN SOL statement list gt 151 HyperSQL SQL Invoked Routines if statement else clause ELSE SQL statement list Return Statement The RETURN statement is required and used only in functions The body of a function is either a RETURN statement or a compound statement that contains a RETURN statement The return value of a FUNCTION can be assigned to a variable or used inside an SQL statement An SQL PSM function or an SQL JRT function can return a single result when the function is defined as RETURNS TABLE To return a table from a SELECT statement you should use a return statement such as RETURN TABLE SELECT in an SQL PSM function For an SQL JRT function the Java method should return a JDBCResultSet instance To call a function from JDBC use a java sql CallableStatement instance The getResultSet call can be used to access the ResultSet returned from a function that returns a result set If the function returns a scalar value the returned result has a single column and a single row which contains the scalar returne
421. n settings such as time zone current schema etc are restored to their original state at the time the session was opened and all open result sets are closed and temporary tables cleared When RESULT SETS is specified all currently open result sets are closed and the resources are released When TABLE DATA is specified the data in all temporary tables is cleared SET AUTOCOMMIT set autocommit command set autocommit statement SET AUTOCOMMIT TRUE FALSE When an SQL session is started by creating a JDBC connection it is in AUTOCOMMIT mode In this mode after each SQL statement a COMMIT is performed automatically This statement changes the mode It is equivalent to using the setAutoCommit boolean autoCommit method of the JOBC Connection object START TRANSACTION start transaction statement start transaction statement i START TRANSACTION lt transaction characteristics gt Start an SQL transaction and set its characteristics All transactional SQL statements start a transaction automatically therefore using this statement is not necessary If the statement is called in the middle of a transaction an exception is thrown SET TRANSACTION set next transaction characteristics lt set transaction statement gt SET LOCAL TRANSACTION transaction characteristics Set the characteristics of the next transaction in the current session This statement has an effect only on the next transa
422. name space within the database The same name cannot be used for a USER and a ROLE Built In Roles and Users There are some pre defined roles in each database some defined by the SQL Standard some by HyperSQL These roles can be assigned to users directly or via other user defined roles In addition there is the initial SYS user created with each new database The initial user name and password is defined in the connection properties when the first connection to the database is made In older versions of HSQLDB this name was always SA But in the latest version the name can be defined as a different string PUBLIC the PUBLIC role The role that is assigned to all authorizations roles and users in the database This role has access rights to all objects in the INFORMATION SCHEMA Any roles or rights granted to this role are in effect granted to all users of the database SYSTEM the SYSTEM role This role is the authorization for the pre defined system objects in the database including the INFORMATION_SCHEMA This role cannot be assigned to any authorization DBA the DBA role HyperSQL specific This is a special role in HyperSQL A user that has this role can perform all possible administrative tasks on the database The DBA role can also act as a proxy for all the roles and users in the database This means it can do everything the authorization for a schema can do including dropping the schema or its objects or granting righ
423. ncremental backup of data file During updates the contents of the data file are modified When this property is true the modified contents are backed up gradually This causes a marginal slowdown in operations but allows fast checkpoint and shutdown When the property is false the data file is backed up entirely at the time of checkpoint and shutdown Up to version 1 8 HSQLDB supported only full backup SET FILES BACKUP INCREMENT TRUE FALSE Table 12 46 Use of Lock File Name Default Description hsqldb lock_file use of lock file can also be used with an existing database By default a lock file is created for each file database that is opened for read and write This property can be specified with the value false to prevent the lock file from being created This usage is not recommended but may be desirable when flash type storage is used This property applies to existing file databases as well as new databases 238 HyperSGL Properties Name Default Description this property cannot be set with an SQL statement Table 12 47 Logging Data Change Statements Name Default Description hsqldb log data logging data change This property can be set to fal se when database recovery in the event of an unexpected crash is not necessary A database that is used as a temporary cache is an example Regardless of the value of this property if there is a prope
424. nd roles on different database objects Refer to the Schemas and Database Objects chapter for a list and description of the tables Example below SELECT FROM INFORMATION SCHEMA SYSTEM USERS SELECT FROM INFORMATION SCHEMA TABLE PRIVILEGES Access Rights By default the objects in a schema can only be accessed by the schema owner But the schema owner can grant privileges access rights on the objects to other users or roles Things can get far more complex because the grant of privileges can be made WITH GRANT OPTION In this case the role or user that has been granted the privilege can grant the privilege to other roles and users Privileges can also be revoked from users or roles The statements for granting and revoking privileges normally specify which privileges are granted or revoked However there is a shortcut ALL PRIVILEGES which means all the privileges that the lt grantor gt has on the schema object The grantor is normally the CURRENT USER of the session that issues the statement The user or role that is granted privileges is referred to as grantee for the granted privileges Table For tables including views privileges can be granted with different degrees of granularity It is possible to grant a privilege on all columns of a table or on specific columns of the table The DELETE privilege applies to the table rather than its columns It applies to all DELETE statements The SELECT INSERT and
425. nd there is no need for subset character sets DROP CHARACTER SET drop character set statement drop character set statement DROP CHARACTER SET character set name Destroy a character set If the character set name is referenced in any database object the command fails Note that CASCADE or RESTRICT cannot be specified for this command CREATE COLLATION collation definition collation definition CREATE COLLATION collation name FOR character set specification FROM existing collation name pad characteristic existing collation name collation name gt pad characteristic NO PAD PAD SPACE Define a collation A new collation is based on an existing COLLATION and applies to an existing CHARACTER SET The character set specification is always SQL TEXT The existing collation name is either SOL TEXT or one of the language collations supported by HSQLDB The pad characteristic specifies whether strings are padded with spaces for comparison This statement is typically used when a collation is required that does not pad spaces before comparing two strings For example CREATE COLLATION FRENCH NOPAD FOR SQL TEXT FROM SQL TEXT NO PAD results in a French collation without padding This collation can be used for sorting or for individual columns of tables DROP COLLATION drop collation statement drop collation statement DROP COLLATION col
426. nder check constraints for more detail about what is not allowed Type declarations in column definition and in cast expressions must have the necessary size parameters e n connection with the above an old database that did not have the enforce strict size property is now converted to version 2 0 with the engine supplying the missing size parameters For example a VARCHAR column declaration that has no size is given a 32K size a LONGVARCHAR column is given a 16MB size Check these sizes are adequate for your use and change the column definition as necessary Column names in a GROUP BY clause were previously resolved to the column label They are now resolved to column name first and if the name does not match to the column label e If two or more tables in a join contain columns with the same name the columns cannot be referenced in join and where conditions Use table names before column names to qualify the references to such columns The SET DATABASE SQL REFERENCES TRUE FALSE statement enables or disables this check f the unqualified wild card is used as in the statement SELECT FROM no additional column references are allowed A table qualified wild card allows additional column references in the SELECT list Table definitions containing GENERATED BY DEFAULT AS IDENTITY but with no PRIMARY KEY do not automatically create a primary key Database script files made with 1 8 are fine as the PRIMARY KEY
427. nection attempts will fail after a few thousand because of OS restrictions on opening sockets and the delay that is built into the OS in closing them Tweaking the Mode of Operation Different modes of operation and settings are used for different purposes Some scenarios are discussed below Application Development and Testing First thing to be aware of is the SQL conformance settings of HyperSQL By default version 2 0 applies stricter conformance rules than version 1 8 and catches long strings or decimal values that do not fit within the specified length or precision settings However there are several conformance settings that are turned off by default This is to enable easier migration from earlier versions and also greater compatibility with databases such as MySQL that are sometimes very liberal with type conversions The conformance settings are listed in the System Management chapter and their connection property equivalents are listed in the Database Properties chapter Ideally all the settings should have a true value for best error checking For application unit testing you can use an all in memory in process database If the tests are all run in one process then the contents of a mem database survives between tests To release the contents you can use the SHUTDOWN command an SQL command You can even use multiple mem databases in your tests and SHUTDOWN each one separately If the tests are in different processes and you wan
428. nection property can be set to alter this amount As any random subset of the rows in any of the CACHED tables can be held in the cache the amount of memory needed by cached rows can reach the sum of the rows containing the largest field data For example if a table with 100 000 rows contains 40 000 rows with 1 000 bytes of data in each row and 60 000 rows with 100 bytes in each the cache can grow to contain 50 000 of the smaller rows but as explained further only 10 000 or the large rows An additional property hsqldb cache_size is used in conjunction with the hsqldb cache_rows property This puts a limit in bytes on the total size of rows that are cached The default values is 10 000KB This is the size of binary images of the rows and indexes It translates to more actual memory typically 2 4 times used for the cache because the data is represented by Java objects If memory is limited the hsqldb cache_rows or hsqldb cache_size database properties can be reduced In the example above if the hsqldb cache_size is reduced from 10 000 to 5 000 it will allow the number of cached rows to reach 50 000 small rows but only 5 000 of the larger rows Data for CLOB and BLOB columns is not cached and does not affect the CACHED table memory cache The use of Java NIO file access method also increases memory usage Access with NIO improves database update speed and is used by default for data files up to 256 MB For minimal memory use nio access should
429. ner See the HyperSQL on UNIX chapter of the HyperSQL User Guide N b You must place this in the right location for your type of UNIX See the init script hsqldb to see where this must be placed and what it should be renamed to This file is sourced by a Bourne shell so use Bourne shell syntax This file WILL NOT WORK until you set at least the non commented variables to the appropriate values for your system Life will be easier if you avoid all filepaths with spaces or any other funny characters Don t ask for support if you ignore this advice aE db db SE 3 The URLIDS setting below is new and REQUIRED This setting replaces the server urlid X settings which used to be needed in your Server s properties file 3 Blaine blaine dot simpson at admc dot com JAVA EXECUTABLE usr bin java Unless you copied the jar files from another system this typically resides at S HSQLDB HOME lib sqltool jar where S HSQLDB HOME is your HSQLDB software base directory The file name may actually have a version label in it like sgltool 1 2 3 jar in which case you must specify the full name here A hsqldb jar file with or without version label must reside in the same directory as the specified sqltool jar file SQLTOOL_JAR_PATH opt hsqldb 2 0 0 hsqldb lib sgltool jar For the sample value above there must also exist a file opt hsqlab 2 0 O hsqldb lib hsqldb jar Where
430. ner in your applications that use embedded databases You can do this by starting up a Server or WebServer instance programmatically but you could also use the class org hsqldb util MainInvoker to start up your application and a HyperSQL Server or WebServer without any programming Example 15 2 MainInvoker Example java cp path to your app jar path to hsqldb jar your App org hsqldb server Server Use instead of to delimit classpath elements on Windows Specify the same in process JDBC URL to your app and in the server properties file You can then connect to the database from outside using a JDBC URL like jdbc hsqldb hsql hostname while connecting from inside the application using something like jdbc hsqldb file filepath of database This tactic can be used to run off the shelf server applications with an embedded HyperSQL Server without doing any coding MainInvoker can be used to run any number of Java class main method invocations in a single JVM See the API specfor MainInvoker for details on its usage Using HyperSQL Without Logging Data Change All file database that are not readonly write changes to the log file There are scenarios where writing to the log file can be turned off to improve performance especially with larger databases For these applications you can set the property hsqldb log data false to disable the recovery log and speed up data change performance The equivalent SQL command is SET FIL
431. new database or opens an existing database i e it is the first connection made to the database by the application all the user defined database properties listed in this section can be specified as URL properties When HSQLDB is used with OpenOffice org as an external database the property default_schema true must be set on the URL otherwise the program will not operate correctly as it does with its built in hsqldb instance 241 HyperSGL Properties System Properties A few system properties are used by HyperSQL These are set on the Java command line or by calling System setProperty from the user s program They are not valid as URL or connection properties Table 12 61 Logging Framework Name Description hsqldb reconfig logging configuring the framework logging Setting this system property false avoids reconfiguring the framework logging system such as Log4J or java util Logging If the property does not exist or is true reconfiguration takes place Table 12 62 Text Tables Name Default Description textdb allow full path text table file locations Setting this system property true allows text table sources to be opened on all available paths By default only the database directory and its subdirectories are allowed See the Text Tables chapter Table 12 63 Java Functions hsqldb method class names allowed Java classes This property needs to be set with the names including wildcar
432. ng Gradle with their IDE But I m going to document a very basic setup done with Eclipse because it s serviceable and a very similar procedure is likely to work with all other IDEs 282 HyperSGL Building HyperSQL Jars If you do use and enjoy Gradle then I urge you to make the product better by registering a free account for yourself at the Gradle Jira site http issues gradle org and vote for critical usability issues like GRADLE 427 http issues gradle org browse GRADLE 427 GRADLE 1855 http issues gradle org browse GRADLE 1855 GRADLE 1870 http issues gradle org browse GRADLE 1870 GRADLE 1871 http issues gradle org browse GRADLE 1871 to help to improve the product Procedure B 1 Invoking Gradle GUI from Windows Explorer 1 Start up Windows explorer Depending on your Windows version it will be in the Start Menu or in the menu you get when you right click Start 2 Navigate Windows Explorer to the build directory within your HyperSQL installation 3 Find an icon or line depending on your Windows Explorer view for the file gradle gui cmd If there is no listing for gradle gui cmd but two listings for gradle gui then you want the one signified by text icon or mouse over tooltip as a batch or CMD file Double click this item Procedure B 2 Setting up Gradle Graphical Builds from Eclipse IDE 1 From Eclipse use pulldown menu Run External Tools External Tools Configurations 2 Right c
433. ng VARCHAR and can be used without specifying the size You can set LONGVARCHAR to map to CLOB with the sq1 1ongvar is lob connection property or the SET DATABASE SQL LONGVAR IS LOB TRUE statement Binary string types are BINARY L VARBINARY L and BLOB Do not use BINARY L unless you are storing keys such as UUID This type pads short binary strings with zero bytes BINARY without the length L means a single byte Use VARBINARY L for general binary strings and BLOB for large binary objects You should apply the same considerations as with the character string types By default LONGVARBINARY is a synonym for a long VARCHAR and can be used without specifying the size You can set LONGVARBINARY to map to BLOB with the sq1l longvar is lob connection property or the SET DATABASE SQL LONGVAR IS LOB TRUE statement The BIT L and BITVARYING L types are for bit maps Do not use them for other types of data BIT without the length L argument means a single bit and is sometimes used as a logical type Use BOOLEAN instead of this type 10 HyperSGL SQL Language The datetime types DATE TIME and TIMESTAMP together with their WITH TIME ZONE variations are available Read the details in this chapter on how to use these types The INTERVAL type is very powerful when used together with the datetime types This is very easy to use but is supported mainly by big iron database systems Note that functions that add days or months to datetime v
434. ng are supported Internal Event Monitoring HyperSQL can log important internal events of the engine These events occur during the operation of the engine and are not always coupled with the exact type of statement being executed Normal events such as opening and closing of files or errors such as OutOfMemory conditions are examples of logged events HyperSQL supports two methods of logging One method is specific to the individual database and is managed internally by HyperSQL The other method is specific to JVM and is managed by a logging framework The internally generated individual log for the database can be enabled with the SET DATABASE EVENT LOG LEVEL statement described in this chapter This method of logging is very useful for desktop application deployment as it provides an ongoing record of database operations 203 HyperSGL System Management Log4J and JDK logging HyperSQL also supports log4J and JDK logging The same event information that is passed to the internal log is passed to external logging frameworks These frameworks are typically configured outside HyperSQL The log messages include the string hsqldb db followed by the unique id a 16 character string of the database that generated the message so they can be identified in a multi database server context As the default JDK logging framework has several shortcomings HyperSQL configures this logging framework fo
435. nly and avoid creating a new database In this case if the database does not exist the get Connection method will throw an exception Example 1 5 specifying a connection property to disallow creating a new database Connection c DriverManager getConnection jdbc hsgldb file opt db testdb ifexists true SA A database has many optional properties described in the System Management chapter You can specify most of these properties on the URL or in the connection properties for the first connection that creates the database See the Properties chapter HyperSQL Chapter 2 SQL Language Fred Toussi The HSQL Development Group Revision 5039 Copyright 2002 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Standards Support HyperSQL 2 0 supports the dialect of SQL defined by SQL standards 92 1999 2003 and 2008 This means where a feature of the standard is supported e g left outer join the syntax is that specified by the standard text Almost all syntactic features of SQL 92 up to Advanced Level are supported as well as SQL 2008 core and many optional features of this standard Work is in progress for a formal declaration of conformance At t
436. nly database is used to open an existing file database This property is a special property that can be added manually to the properties file or included in the URL or connection properties When this property is true the database becomes readonly This can be used with an existing database to open it for readonly operation this property cannot be set with an SQL statement it can be used in the properties file Table 12 35 Opening Database Without Modifying the Files Name Default Description files readonly readonly files database is used to open an existing file database This property is used similarly to the hsqldb readonly property When this property is true CACHED and TEXT tables are readonly but memory tables are not Any change to the data is not persisted to database files this property cannot be set with an SQL statement it can be used in the properties file Table 12 36 Huge database files and tables Name Default Description hsqldb large data enable huge database files By default up to 2 billion rows can be stored in disk based CACHED tables Setting this property to true increases the limit to 512 billion rows This property is used as a connection property this property cannot be set with an SQL statement it can be used as a connection property for the connection that opens the database Table 12 37 Temporary Result Rows in Memor
437. nt filtered counts SELECT COUNT ITEM FILTER WHERE GENDER F AS FEMALE COUNT COUNT ITEM FILTER WHERE GENDER M AS MALE COUNT FROM PEOPLE ARRAY AGGis different from all other aggregate functions as it does not ignore the NULL values This set function returns an array that contains all the values for different rows for the value expression For example if the value expression isa column reference the SUM function adds the values for all the row together while the ARRAY AGG function adds the value for each row as a separate element of the array ARRAY AGG can include an optional order by clause If this is used the elements of the returned array are sorted according to the order by clause which can reference all the available columns of the query not just the value expression thatis used as the ARRAY AGG argument The order by clause can have multiple elements and each element can include NULLS LAST or DESC qualifiers No separator is used with this function GROUP CONCAT is a specialised function derived from ARRAY AGG This function computes the array in the same way as ARRAY AGG removes all the NULL elements then returns a string that is a concatenation of the elements of the array If separator has been specified it is used to separate the elements of the array Otherwise the comma is used to separate the elements The example below shows a grouped query with ARRAY AGG and GROU
438. ntil the session is closed or the next use of this command The current read only mode can be accessed with the ISREADONLYO function Example 3 6 Setting Session Characteristics SET SESSION CHARACTERISTICS AS TRANSACTION READ ONLY SET SESSION CHARACTERISTICS AS TRANSACTION ISOLATION LEVEL SERIALIZABLE SET SESSION CHARACTERISTICS AS TRANSACTION READ WRITE ISOLATION LEVEL READ COMMITTED SET SESSION AUTHORIZATION set session user identifier statement lt set session user identifier statement gt SET SESSION AUTHORIZATION lt value specification gt Set the SQL session user identifier This statement changes the current user The user that executes this command must have the CHANGE_AUTHORIZATION role or the DBA role After this statement is executed all SQL statements are executed with the privileges of the new user The current authorisation can be accessed with the CURRENT_USER and SESSION_USER functions Example 3 7 Setting Session Authorization SET SESSION AUTHORIZATION FELIX SET SESSION AUTHORIZATION SESSION_USER SET ROLE set role statement 39 HyperSGL Sessions and Transactions set role statement SET ROLE role specification 5 role specification value specification NONI Set the SQL session role name and the current role name for the current SQL session context The user that executes this command must have the specified role If NON
439. ntinues to the next field Otherwise the result of the last performed comparison is returned as the result of the predicate This means that if the first field is NULL the result is always UNKNOWN The logic that governs NULL values and UNKNOWN result is as follows Suppose the NULL values were substituted by arbitrary real values If substitution cannot change the result of the predicate then the result is TRUE or FALSE based on the existing non NULL values otherwise the result of the predicate is UNKNOWN 111 HyperSGL Data Access and Change The examples of comparison given below use literals but the literals actually represent the result of evaluation of some expression Gl 2 3 Me PE EHE DEETSSEREUE Gl 2 3 4 di 2 s 9 16 ALSH Gl 25 3 x Gly 2 Sp yy Sus ME ATIS Bi Gl 2 3 4 lt o 2 3 S ws 15589 NULL 1 NULL NULL 1 NULL IS UNKNOWN NULL 1 NULL NULL 2 NULL IS FALSE NULL 1 NULL lt gt NULL 2 NULL IS TRUE NULL 1 2 lt all operators gt NULL 1 2 IS UNKNOWN 1 NULL lt L 2 IS UNKNOWN Gl NUTT NE RE M OF IN in ni asol ES ER UE CA Wot ceo lt ly IN a cool 1S TADS BETWEEN between predicate lt between predicate gt lt row value predicand gt lt between predicate part 2 gt between predicate part 2 gt NOT BETWEEN ASYMMETRIC SYMMETRIC row value predicand gt
440. o be created used in SELECT or other statements combined with rows of tables and used in routine calls Array Definition The type of a table column a routine parameter a variable or the return value of a function can be defined as an array array type data type ARRAY left bracket or trigraph maximum cardinality right bracket or trigraph The word ARRAY is added to any valid type definition except BLOB and CLOB type definitions If the optional maximum cardinality is not used the default value is 1024 The size of the array cannot be extended beyond maximum cardinality In the example below the table contains a column of integer arrays and a column of varchar arrays The VARCHAR array has an explicit maximum size of 10 which means each array can have between 0 and 10 elements The INTEGER array has the default maximum size of 1024 The scores column has a default clause with an empty array The default clause can be defined only as DEFAULT NULL or DEFAULT ARRAYT and does not allow arrays containing elements CREATE TABLE t id INT PRIMARY KEY scores INT ARRAY DEFAULT ARRAY names VARCHAR 20 ARRAY 10 An array can be constructed from value expressions or a query expression 23 HyperSGL SQL Language array value constructor by enumeration ARRAY left bracket or trigraph array element list right bracket or trigraph array element list value expression
441. ocking 2PL which is the default multiversion concurrency control MVCC and a hybrid model which is 2PL plus multiversion rows Within each model it supports some of the 4 standard levels of transaction isolation READ UNCOMMITTED READ COMMITTED REPEATABLE READ and SERIALIZABLE The concurrency control model is a strategy that governs all the sessions and is set for the database as opposed for individual sessions The isolation level is a property of each SQL session so different sessions can have different isolation levels In the new implementation all isolation levels avoid the dirty read phenomenon and do not read uncommitted changes made to rows by other transactions HyperSQL is fully multi threaded in all transaction models Sessions continue to work simultaneously and can fully utilise multi core processors To concurrency control model of a live database can be changed The SET DATABASE TRANSACTION CONTROL LOCKS MVLOCKS MVCC can be used by a user with the DBA role Two Phase Locking The two phase locking model is the default mode It is referred to by the keyword LOCKS In the 2PL model each table that is read by a transaction is locked with a shared lock read lock and each table that is written to is locked with an exclusive lock write lock If two sessions read and modify different tables then both go through simultaneously If one session tries to lock a table that has been locked by the other if both locks ar
442. of the next statement the MAXROWS limit is removed Only zero or positive values can be used with this command The value overrides any value specified with setMaxRows int max method of a JDBC statement The statement SET MAXROWS 0 means no limit It is possible to limit the number of rows returned from SELECT statements with the FETCH lt n gt ROWS ONLY or its alternative LIMIT lt n gt Therefore this command is not recommended for general use The only legitimate use of this command is for checking and testing queries that may return very large numbers of rows SET SESSION RESULT MEMORY ROWS set session result memory rows statement lt set session result memory rows statement gt SET SESSION RESULT MEMORY ROWS lt unsigned integer literal gt By default the session uses memory to build result sets subquery results and temporary tables This command sets the maximum number of rows of the result and temporary tables that should be kept in memory If the row count of the result or temporary table exceeds the setting the result is stored on disk The default is 0 meaning all result sets are held in memory This statement applies to the current session only The general database setting is Eal SET DATABAS DEFAULT RESULT MEMORY ROWS lt unsigned integer literal gt SET IGNORECASE set ignore case statement LA set ignore case statement gt SET IGNORECA
443. ohibited by an ACL rule 251 HyperSQL Chapter 14 HyperSQL on UNIX How to quickly get a HyperSQL aka HSQLDB Listener up and running on UNIX including Mac OS X Blaine Simpson The HSQL Development Group Revision 4907 2012 08 06 00 12 50 0100 Purpose This chapter explains how to quickly install run and use a HyperSQL Listener aka Server on UNIX Note that unlike a traditional database server there are many use cases where it makes sense to run HyperSQL without any listener This type of setup is called in process and is not covered here since there is no UNIX specific setup in that case I intend to cover what I think is the most common UNIX setup To run a multi user externally accessible catalog with permanent data persistence By the latter I mean that data is stored to disk so that the catalog data will persist across process shutdowns and startups I also cover how to run the Listener as a system daemon When I give sample shell commands below I use commands which will work in Bourne compatible shells including Bash and Korn Users who insist on using the inferior C shells will need to convert Installation Go to http sourceforge net projects hsqldb and click on the files link You want the current version I can t be more specific because SourceForge Geeknet are likely to continue changing their interface See if there s a distribution for the current HSQLDB version in the format that you wan
444. oined table All join operators are evaluated left to right therefore with multiple joins the table resulting from the first join operator becomes an operand of the next join operator Parentheses can be used to group sequences of joined tables and change the evaluation order So if more than two tables are joined together with join operators the end result is also a joined table There are different types of join each producing the result table in a different way 124 HyperSGL Data Access and Change joined table cross join qualified join natural join Cross join table reference CROSS JOIN table factor qualified join table reference join type JOIN table reference join specification natural join table reference NATURAL join type JOIN table factor gt join specification gt join condition lt named columns join join condition ON search condition named columns join USING left paren join column list right paren join type INNER outer join type OUTER lt outer join type LEFT RIGHT FULL join column list column name list CROSS JOIN The simplest form of join is CROSS JOIN The CROSS JOIN of two tables is a table that has all the columns of the first table followed by all the columns of the second table in the original order Each row of the first
445. ol2 FROM atable WHERE id 10 In the example below the result of a function call is assigned to VARI SET varl SORT var2 i Select Statement Single Row A special form of SELECT can also be used for assigning values from a query to one or more arguments or variables This works similar to a SET statement that has a SELECT statement as the source SELECT SINGLE ROW select statement single row lt select statement single row gt SELECT lt set quantifier gt lt select list gt INTO lt select target list gt lt table expression gt lt select target list target specification comma target Specification Retrieve values from a specified row of a table and assign the fields to the specified targets The example below has an identical effect to the example of SET statement given above SELECT coli col2 INTO argl arg2 FROM atable WHERE id 10 Formal Parameters Each parameter of a procedure can be defined as IN OUT or INOUT An IN parameter is an input to the procedure and is passed by value The value cannot be modified inside the procedure body An OUT parameter is a reference 148 HyperSQL SQL Invoked Routines for output An INOUT parameter is a reference for both input and output An OUT or INOUT parameter argument is passed by reference therefore only a dynamic parameter argument or a variable within an enclosing procedure can be passed f
446. ols are run in the normal way for Java programs In the following example the Swing version of the Database Manager is executed The hsqldb jar is located in the directory lib relative to the current directory java cp lib hsqldb jar org hsqldb util DatabaseManagerSwing If hsqldb jar is in the current directory the command would change to java cp hsqldb jar org hsqldb util DatabaseManagerSwing Main classes for the Hsqldb tools e org hsgqldb util DatabaseManager e org hsqldb util DatabaseManagerSwing When a tool is up and running you can connect to a database may be a new database and use SQL commands to access and modify the data HyperSGL Running and Using HyperSQL Tools can use command line arguments You can add the command line argument help to get a list of available arguments for these tools Double clicking the HSQLDB jar will start the DatabaseManagerSwing application A HyperSQL Database Each HyperSQL database is called a catalog There are three types of catalog depending on how the data is stored Types of catalog data mem stored entirely in RAM without any persistence beyond the JVM process s life file stored in filesystem files res stored in a Java resource such as a Jar and always read only All in memory mem catalogs can be used for test data or as sophisticated caches for an application These databases do not have any files A file
447. ome elements of SQLServer syntax Single row SELECT statements SELECT expression list without the FROM clause are supported and treated as the SQL Standard equivalent VALUES expression list The parameters of CONVERTO function are switched in this mode The property is FALSE by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sql syntax mss SET DATABASE SQL SYNTAX MYS set database sql syntax MYS set database sql syntax MYS statement SET DATABASE SQL SYNTAX MYS TRUE FALSE This property when set TRUE enables support for some elements of MySQL syntax The TEXT data type is translated to LONGVARCHAR In CREATE TABLE statements NOT NULL NULL can be used immediately after the column type name and before the DEFAULT clause AUTO_INCREMENT is translated to the GENERATED BY DEFAULT AS IDENTITY clause Single row SELECT statements SELECT expression list without the FROM clause are supported and treated as the SQL Standard equivalent VALUES lt expression list gt The property is FALSE by default Only a user with the DBA role can execute this statement 219 HyperSGL System Management This is equivalent to the connection property sql syntax mys SET DATABASE SQL SYNTAX ORA set database sql syntax ORA set database sql syntax ORA statement SET DATABASE SQL SYNTAX ORA TRUE FALSE
448. on 175 MATCH predicate 114 MAX CARDINALITY function 190 memory use 266 MERGE INTO 135 MINUTE function 184 MOD function 180 MONTH function 185 MONTHNAME function 185 N name resolution 128 naming in joined table 127 naming in select list 127 NATURAL JOIN 125 NEXT VALUE FOR 107 NOW function 183 NULLIF function 193 NULL INPUT 142 numeric literal 101 NUMERIC types 11 numeric value expression 108 numeric value function 108 NVL2 function 193 NVL function 193 O OCTET_LENGTH function 175 OTHER type 16 OUTER JOIN 126 OVERLAPS predicate 115 OVERLAY function 175 P PARAMETERS 77 password complexity 205 PATH 118 PI function 180 POSITION_ARRAY function 190 POSITION function 175 POWER function 180 PRIMARY KEY constraint 56 304 HyperSQL General Index PUBLIC ROLE 88 Q QUARTER function 185 R RADIANS function 180 RAND function 180 RAWTOHEX function 175 REFERENTIAL_CONSTRAINTS 77 REGEXP_MATCHES function 175 REGEXP_SUBSTRING_ARRAY function 176 REGEXP_SUBSTRING function 176 RELEASE SAVEPOINT 38 RENAME 51 REPEAT UNTIL loop in routines 149 REPEAT function 176 REPLACE function 176 RESIGNAL STATEMENT 153 RETURN 152 RETURNS 139 REVERSE function 176 REVOKE 93 REVOKE ROLE 93 RIGHT function 176 ROLE_AUTHORIZATION_DESCRIPTORS 77 ROLE_COLUMN_GRANTS 77 ROLE_ROUTINE_GRANTS 77 ROLE TABLE GRANTS 77 ROLE UDT GRANTS 77 RO
449. on is equivalent to EXTRACT QUARTER FROM Returns an integer in the range of 1 4 JDBC SECOND SECOND datetime valu xpr gt This function is equivalentto EXTRACT SECOND FROM Returns an integer or decimal in the range of 0 59 with the same precision as the datetime value expr gt JDBC SECONDS SINCE MIDNIGHT SECONDS SINCE MIDNIGHT datetime valu xpr gt This function is equivalent to EXTRACT SECONDS SINCE MIDNIGHT FROM Returns an integer in the range of 0 86399 HyperSQL UNIX TIMESTAMP UNIX TIMESTAMP datetime valu xpression gt This function returns a BIGINT value With no parameter it returns the number of seconds since 1970 01 01 With a DATE or TIMESTAMP parameter it converts the argument into number of seconds since 1970 01 01 The TIMESTAMP num value expression function returns a TIMESTAMP from a Unix timestamp HyperSQL WEEK WEEK datetime valu xpr gt This function is equivalent to EXTRACT WEEK OF YEAR FROM Returns an integer in the range of 1 54 JDBC YEAR YEAR datetime valu xpr gt This function is equivalentto EXTRACT YEAR FROM Returns an integer in the range of 9999 JDBC EXTRACT 185 HyperSGL Built In Functions EXTRACT extract field FROM extract source extract field YEAR MONTH DAY HOUR MINUTE DAY
450. on mechanism is used to determine which database objects the particular user can access The default authentication mechanism is password authentication Each user is created with a password which is stored in the database and checked each time a new database connection is created Password Complexity Check HyperSQL allows you to define a function that checks the quality of the passwords defined in the database The passwords are stored in the database Each time a user connects the user s name and password are checked against the stored list of users and passwords The connection attempt is rejected if there is no match External Authentication You can use an external authentication mechanism instead of the internal authentication mechanism HyperSQL allows you to define a function that checks the combination of database unique name user name and password for each connection attempt The function can use external resources to authenticate the user For example a directory server may be used The password may be ignored if the external resource can verify the user s credential without it You can override external authentication for a user with the ALTER USER statement See the Access Control chapter Compatibility with Other RDBMS HyperSQL is used more than any other database engine for application testing and development targeted at other databases Over the years this usage resulted in developers finding and reporting many obscure bugs in
451. on table or variable transition table or variable OLD ROW AS old transition variable name NEW ROW AS new transition variable name OLD TABLE AS old transition table name NEW TABLE AS new transition table name old transition table name transition table name new transition table name transition table name transition table name identifier old transition variable name correlation name new transition variable name correlation name Trigger definition is a relatively complex statement The combination of trigger action time and trigger event determines the type of the trigger Examples include BEFORE DELETE AFTER UPDATE INSTEAD OF INSERT If the optional OF trigger column list is specified for an UPDATE trigger then the trigger is activated only if one of the columns that is in the trigger column list is specified in the UPDATE statement that activates the trigger Ifatriggeris FOR EACH ROW which is the default option then the trigger is activated for each row of the table that is affected by the execution of an SQL statement Otherwise it is activated once only per statement execution For FOR EACH ROW triggers there is an OLD and NEW state for each row For UPDATE triggers both OLD and NEW states exist representing the row before the update and after the update For DELETE triggers there is only a
452. onal dependency relationship exists between these columns and the other columns in that query expression then the VIEW or other schema object will be dropped when CASCADE is specified ALTER COLUMN alter column definition alter column definition ALTER COLUMN column name alter column action alter column action set column default clause drop column default clause alter column data type clause alter identity column specification alter column nullability alter column name add column identity Specification drop column identity specification Change a column and its definition Specific types of this statement are covered below See also the RENAME statement above SET DEFAULT set column default clause set column default clause SET default clause Set the default clause for a column This can be used if the column is not defined as GENERATED DROP DEFAULT drop column default clause drop column default clause DROP DEFAULT Drop the default clause from a column SET DATA TYPE alter column data type clause I alter column data type clause SET DATA TYPE data type Change the declared type of a column The proposed SQL Standard allows only changes to type properties such as maximum length precision or scale and only changes that cause the property to enlarge HyperSQL allows changing the type if all the
453. onnection jdbc hsqldb http localhost xdb SA Note in the above connection URL there is no mention of the database file as this was specified when running the server Instead the public name defined for dbname O is used Also see the HyperSQL Network Listeners Servers chapter for the connection URL when there is more than one database per server instance Security Considerations When a HyperSQL server is run network access should be adequately protected Source IP addresses may be restricted by use of our Access Control List feature network filtering software firewall software or standalone firewalls Only secure passwords should be used most importantly the password for the default system user should be changed from the default empty string If you are purposefully providing data to the public then the wide open public network connection should be used exclusively to access the public data via read only accounts i e neither secure data nor privileged accounts should use this connection These considerations also apply to HyperSQL servers run with the HTTP protocol HyperSQL provides two optional security mechanisms The encrypted SSL protocol and Access Control Lists Both mechanisms can be specified when running the Server or WebServer On the client the URL to connect to an SSL server is slightly different Example 1 3 Java code to connect to the local secure SSL hsql and http Servers Connection
454. ons are supported The DUAL table and the expressions ROWNUM CURRVAL NEXTVAL are supported in DB2 syntax mode SQL routines are highly portable with minimal change MS SQLServer and Sybase Compatibility SQLServer has some incompatibilities with the Standard syntax The most significant is the use of square brackets instead of double quotes for case sensitive column names Use set database sql syntax MSS statement to enable support for the CONVERT type definition expression function with switched order of arguments Use MVCC with set database transaction control statement if your application is multi user If you use the non standard concatenation of possibly NULL values in your select statements you may need to change the setting for set database sql concat nulls statement HyperSQL supports for string concatenation It also supports many functions supported by these dialects SQLServer uses a non standard expression SELECT A Test String to return a single row table The standard form is VALUES A Test String In MSS syntax mode this type of SELECT is supported SQL routines need quite a lot of changes Statements System level statements are listed in this section Statements that begin with SET DATABASE or SET FILES are for properties that have an effect on the normal operation of HyperSQL The effects of these statements are also discussed in different chapters System Operations
455. ooouosoouoseooosooanoooouose 279 List of SQL Keywords Disallowed as HyperSQL Identifiers eee 280 Special Function Key Words vii cs8 ewe teye nette rhone tete Le deeb sibs ode eae Re Done iesu ST ON ke 281 B Building Ay perSQly Jats scsicesuecinsssnencsosvsess sence sane sviedensy pe Aves veu peu ES E EET EE EREE E ETE 282 anno ETT 282 Building With Grade 11er droite ewedes sen tet red eos reret e des casse etes vie stdoni pas taste dures E vant enan 282 Invoking a Gradle Build Graphically esee 282 Invoking a Gradle Build from the Command Line esesseee HH 285 Using Gra dle eeir ieren i teste stan eee rai ti n e n A dtes tet n ka diues ee e di it de vate kip dux ces 286 B ilding With ui Km 288 Obtaminp Ant 1m ode ded ins de tre dua da dhe SO dea d teen E duct I pab 288 Binlding Hsqldb With Ant eoe ette oett oet Inter err esae bh co 2v terrea e Su edes supr esos epe EE 288 hls hicC aS 289 Building with IDE Compllers wes se ete eto toe eite haee epe eee e ete tdg diese ee kask qe recu ERU seye 289 Hsgldb CoOdeS imr Pcr 290 Building Documentation rm 291 C HyperSQL with OpenOffice 1 icta eoe beet eee idee tese te ee tesa Li Fuel tegere sta de ee setae Sesi an papi a 293 HypeiSQL vnth OpenOfflCe 5er terrae rta ere eei t ente e sann peniw isi endesan pie pasaje sikse pan 293 Using OpenOffice LibreOffice as a Database Tool 293 Converting odb files to use with Hy
456. operty sql enforce size SET DATABASE SQL NAMES set database sql names statement set database sql names statement SET DATABASE SQL NAMES TRUE FALSE Enable or disable full enforcement of the rule that prevents SQL keywords being used for database object names such as columns and tables The default is FALSE meaning disabled SQL Standard requires enforcement It is better to enable this check in order to improve the quality and correctness of SQL statements Only a user with the DBA role can execute this statement This is equivalent to the connection property sql enforce names 214 HyperSGL System Management SET DATABASE SQL REGULAR NAMES set database sql regular names statement set database sql regular names statement SET DATABASE SQL REGULAR NAMES TRUE FALSE Enable or disable use of the underscore character at the beginning or the dollar character anywhere in database object names such as columns and tables The default is TRUE meaning disabled SQL Standard does not allow the underscore character at the start of names and does not allow the dollar character anywhere in a name This setting can be changed for compatibility with existing database or for porting databases which include names that do not conform to the Standard Only a user with the DBA role can execute this statement This is equivalent to the connection property sql regula
457. or identifiers chains composed of single identifiers chained together with the period symbol identifier chain identifier chain identifier chain identifier period identifier basic identifier chain identifier chain 103 HyperSGL Data Access and Change A period separated chain of identifiers The identifiers in an identifier chain can refer to database objects in a hierarchy The possible hierarchies are as follows In each hierarchy elements from the start or the end can be missing but the order of elements cannot be changed catalog schema database object catalog schema table column correlation name column Examples of identifier chain are given below SELECT MYCAT MYSCHEMA MYTABLE MYCOL FROM MYCAT MYSCHEMA MYTABLE DROP TABLE MYCAT MYSCHEMA MYTABLE CASCADE ALTER SEQUENCE MYCAT MYSCHEMA MYSEQUENCE RESTART WITH 100 column reference column reference E lt column reference lt basic identifier chain MODULI identifier gt lt period gt lt column name gt lt period gt lt qualified Reference a column or a routine variable SQL parameter reference SQL parameter reference lt SQL parameter reference gt lt basic identifier chain gt Reference an SQL routine parameter contextually typed value specification contextually typed value specification lt contextually typed value specification gt lt null speci
458. or it The assignment statement is used to assign a value to an OUT or INOUT parameter In the example below the procedure is declared with an OUT parameter It assigns the auto generated IDENTITY value from the INSERT statement to the OUT argument CREATE PROCEDURE new customer OUT newid INT IN firstname VARCHAR 50 IN lastname VARCHAR 50 IN address VARCHAR 100 MODIFIES SQL DATA BEGIN ATOMIC DECLARE temp_id INTEGER INSERT INTO CUSTOMERS VALUES DEFAULT firstname lastname CURRENT_TIMESTAMP SET temp_id IDENTITY INSERT INTO ADDRESSES VALUES DEFAULT temp_id address SET newid temp_id END In the SQL session or in the body of another stored procedure a variable must be assigned to the OUT parameter After the procedure call this variable will hold the new identity value that was generated inside the procedure If the procedure is called directly using the JDBC CallableStatement interface then the value of the first OUT argument can be retrieved with a call to get Int 1 after calling the execute method In the example below a session variable the new id is declared After the call to new customer the value for the identity is stored in the new id variable This is returned via the next CALL statement Alternatively the new id can be used as an argument to another CALL statement DECLARE the new id INT DEFAULT NULL CALL new customer the new id John Smith 10 Parliament Square CALL th
459. ormat The qualifier BLOCKING means all database operations are suspended during backup During backup a CHECKPOINT command is silently executed This mode is always used when SCRIPT is specified Hot backup is performed if NOT BLOCKING is specified In this mode the database can be used during backup This mode should only be used with very large databases A hot backup set is less compact and takes longer to restore and use than a normal backup set produced with the BLOCKING option You can perform a CHECKPOINT just before a hot backup in order to reduce the size of the backup set 210 HyperSGL System Management The HyperSQL jar also contains a program that creates an archive of an offline database It also contains a program to expand an archive into database files These programs are documented in this chapter under Backing up Database Catalogs Only a user with the DBA role can execute this statement CHECKPOINT checkpoint statement checkpoint statement CHECKPOINT DEFRAG Closes the database files rewrites the script file deletes the log file and opens the database If DEFRAG is specified also shrinks the data file to its minimum size Only a user with the DBA role can execute this statement Only a user with the DBA role can execute this statement SCRIPT script statement script statement SCRIPT file name gt Returns a script containing SQL statements that define the database
460. out referencing schema objects These are AUTHORIZATIONS and ADMINSTRABLE ROLE AUTHORIZATIONS Also below the top level there is the SCHEMATA view which lists the schemas in the catalog The views that refer to top level schema objects are divided by object type These includes ASSERTIONS CHARACTER SETS COLLATIONS DOMAINS ROUTINES SEQUENCES TABLES USER DEFINED TYPES and VIEWS There are views that refer to objects that are dependent on the top level schema objects These include COLUMNS and PARAMETERS views for constraints including CHECK CONSTRAINTS REFERENTIAL CONSTRAINTS and TABLE CONSTRAINTS and finally the TRIGGERS view The usage of each type of top level object by another is covered by several views For example TRIGGER SEQUENCE USAGE or ROUTINE TABLE USAGE Several other views list the individual privileges owned or granted to each AUTHORIZATION For example ROLE ROUTINE GRANTS or TABLE PRIVILEGES 74 HyperSGL Schemas and Database Objects Data Type Information The INFORMATION SCHEMA contains comprehensive information on the data types of each schema object and its elements For example the ROUTINES view includes the return data type for each FUNCTION definition The columns for this information contain nulls for rows that cover PROCEDURE definitions The COLUMNS PARAMETERS and SEQUENCES views contain the type information in columns with similar names The type information for ARRAY types is returned in t
461. overall performance may be higher when fewer simultaneous connections are used If you want to reduce the number of simultaneous sessions you can use a connection pool with fewer pooled connections An application that is not both multi threaded and transactional such as an application for recording user login and logout actions does not need more than one connection The connection can stay open indefinitely and reopened only when it is dropped due to network problems When using an in process database when the last connection to the database is closed the database still remains open waiting for the next connection to be made From version 2 2 9 each time the last connection is closed all the data changes are logged and synched to disk An explicit SHUTDOWN command with or without an argument is required to close the database A connection property shutdown true can be used on the connection URL or in a properties object to shutdown the database when the last connection is closed When using a server database and to some extent an in process database care must be taken to avoid creating and dropping JDBC Connections too frequently Failure to observe this will result in poor performance when the application is under heavy load 268 HyperSQL Deployment Guide A common error made by users in load test simulations is to use a single client machine to open and close thousands of connections to a HyperSQL server instance The con
462. overy Log PrOC6SSIDB 14 erento edat te etuer EE vetus se done sar pee ee voe PER e vetu kad ede ERN seen 240 12 55 Default Properties for TEXT Tables eere etm ree danh ne eene ye eye 240 12 56 Forcing Garbage ColleCHON 1 isecro te reto rette ro peine a dee Eee v voe e vos Sb pa eere Ue souke les duke sius Poesie reps 240 12 57 Crypt Property For EOBS iicet peccet e RUE E eco utet esed etta Ud KR eae gasses 241 12 58 Cipher Key for Encrypted Database sessssesee eee eee hen hee hene hene 241 12 59 Crypt Provider Encrypted Database esses oo ae oo neoo aso esooesooeoooeoonsoonsoonsoonsoonooue 241 12 60 Cipher Specification for Encrypted Database llleeeleeeoeeeoooeoooesooesoneoonsoonsonnoonnsoneoonooonoooe 241 12 61 Logging dcin Ui dM mE 242 I MI suJI d I 242 12 63 Java PUNCHONS Rx 242 13 1 common server and webserver properties Hem emen hene rentre 244 ME aad D ko at go a e e a a co a e e ok epa L ka e A A ERE a ke ak pe S pa ee aa 245 13 3 webserver properties espcr s eccesso tico pr bete cat Peter stg excu det eacd v le kata aaa see ea ves etae pex vede bee o ok 245 xi HyperSQL List of Examples 1 1 Java code to connect to the local hsql Server He emere 5 1 2 Java code to connect to the local http Server Hehe heme 5 1 3 Java code to connect to the local secure SSL hsql and http Servers
463. ovy Dependency using Grape GGrab group org hsqldb module hsqldb version 2 classifier jdk6debug 278 HyperSQL Appendix A Lists of Keywords List of SQL Keywords Fred Toussi The HSQL Development Group Revision 847 2012 08 06 00 12 50 0100 List of SQL Standard Keywords According to the SQL Standard the SQL Language keywords cannot be used as identifiers names of database objects such as columns and tables without quoting HyperSQL has two modes of operation which are selected with the SET DATABASE SQL NAMES TRUE FALSE to allow or disallow the keywords as identifiers The default mode is FALSE and allows the use of most keywords as identifiers Even in this mode keywords cannot be used as USER or ROLE identifiers When the mode is TRUE none of the keywords listed below can be used as identifiers All keywords can be used with double quotes as identifiers For example CREATE TABLE ALL AND INT WHEN INT SELECT AND FROM ALL WHERE WHEN 2020 ABS ALL ALLOCATE ALTER AND ANY ARE ARRAY AS ASENSITIVE ASYMMETRIC AT ATOMIC AUTHORIZATION AVG BEGIN BETWEEN BIGINT BINARY BLOB BOOLEAN BOTH BY CALL CALLED CARDINALITY CASCADED CASE CAST CEIL CEILING CHAR CHAR LENGTH e CHARACTER CHARACTER LENGTH CHECK CLOB CLOSE COALESCE COLLATE COLLECT COLUMN COMMIT COMPARABLE CONDITION CONNECT
464. ows SET DATABASE DEFAULT RESULT MEMORY ROWS unsigned integer literal Sets the maximum number of rows of each result set and internal temporary table that is held in memory Temporary tables includes views schema based and session based TEMPORARY tables transient tables for subqueries and INFORMATION SCHEMA tables This setting applies to all sessions Individual sessions can change the value with the SET SESSION RESULT MEMORY ROWS statement The default is 0 meaning all result sets are held in memory Only a user with the DBA role can execute this statement This is equivalent to the connection property hsgldb result max memory rows SET DATABASE DEFAULT TABLE TYPE set database default table type statement I set database default table type SET DATABASE DEFAULT TABLE TYPE CACHED MEMORY j Sets the type of table created when the next CREATE TABLE statement is executed The default is MEMORY Only a user with the DBA role can execute this statement This is equivalent to the connection property hsqldb default table type SET DATABASE EVENT LOG LEVEL set database event log level statement Eal ll a ET DATABASI set database event log level LI 2 3 3 EVENT LOG SQL LEVEL 0 When the SQL option is not used this statement sets the amount of information logged in the internal database specific event log Level
465. p to 5 files in the same directory with the endings such as properties script etc as detailed in previous chapters HyperSQL 2 2 includes commands to backup the database files into a single tar or tar gz file archive The backup can be performed by a command given in a JDBC session if the target database catalog is running or on the command line if the target catalog has been shutdown Making Online Backups To back up a running catalog obtain a JDBC connection and issue a BACKUP DATABASE command in SQL In its most simple form the command format below will backup the database as a single tar gz file to the given directory BACKUP DATABASE TO directory name BLOCKING The directory name must end with a slash to distinguish it as a directory and the whole string must be in single quotes like so subdir nesteddir See the next section under Statements for details about the command and its options See the sections below about restoring a backup Making Offline Backups To back up an offline catalog the catalog must be in shut down state You will run a Java command like this In this example the database is named dbname and is in the dbdir directory The backup is saved to a file named backup tar in the tardir directory Example 11 2 Offline Backup Example java cp hsqldb jar org hsqldb lib tar DbBackup save tardir backup tar dbdir dbname where tardir backup tar isa file path to th
466. pear in the second table The type of each shared column of the joined table is based on the type of the columns in the original tables If the original types are not exactly the same the type of the shared column is formed by type aggregation Type aggregations selects a type that can represent values of both aggregated types Simple type aggregation picks one of the types For example SMALLINT and INTEGER results in INTEGER or VARCHAR 10 and VARCHAR 20 results in VARCHAR 20 More complex type aggregation inherits properties from both types For example DECIMAL 8 and DECIMAL 6 2 results in DECIMAL 8 2 In the examples below the rows are joined exactly the same way but the first query contains a col two and b col two together with all the rest of the columns of both tables while the second query returns only one copy of col two SELECT FROM a INNER JOIN b ON a col two b col two SELECT FROM a INNER JOIN b USING col two OUTER JOIN LEFT RIGHT and FULL OUTER JOIN The three qualifiers can be added to all types of JOIN except CROSS JOIN and UNION JOIN First the new table is populated with the rows from the original join If LEFT is specified all the rows from the first table that did not make it into the new table are extended to the right with nulls and added to the table If RIGHT is specified all the rows from the second table that did not make it into the new table are extended to the left with nulls and added to the
467. pecified with the optional SET clause I I resignal statement RESIGNAL SOLSTATE state value SET MESSAGE TEXT character string literal Routine Polymorphism More than one version of a routine can be created For procedures the different versions must have different parameter counts When the procedure is called the parameter count determines which version is called For functions the different versions can have the same or different parameter counts When the parameter count of two versions of a function is the same the type of parameters must be different When the function is called the best matching version of the function is used according to both the parameter count and parameter types The return type of different versions of a function can be the same or different Two versions of an overloaded function are given below One version accepts TIMESTAMP while the other accepts TIME arguments CREATE FUNCTION an hour before or now t TIMESTAMP RETURNS TIMESTAMP IF t CURRENT TIMESTAMP THEN RETURN CURRENT TIMESTAMP ELSE RETURN t 1 HOUR 153 HyperSQL SQL Invoked Routines END IF CREATE FUNCTION an hour before or now t TIME RETURNS TIME CASE t WHEN CURRENT TIME THEN RETURN CURRENT TIME WHEN TIME 01 00 00 THEN RETURN t 1 HOUR ELSE RETURN CURRENT TIME END CASE It is perfectly possible to have different versions of the routine as SQL
468. perSGL Data Access and Change JDBC Parameters When a JDBC PreparedStatement or CallableStatement is used with an SQL statement that contains dynamic parameters the data types of the parameters are resolved and determined by the engine when the statement is prepared The SQL Standard has detailed rules to determine the data types and imposes limits on the maximum length or precision of the parameter HyperSQL applies the standard rules with two exceptions for parameters with String and BigDecimal Java types HyperSQL ignores the limits when the parameter value is set and only enforces the necessary limits when the PreparedStatement is executed In all other cases parameter type limits are checked and enforce when the parameter is set In the example below the setString calls do not raise an exception but one of the execute statements does table definition CREATE TABLE T NAME VARCHAR 12 Connection c newConnection PreparedStatement st c prepareStatement SELECT FROM T WHERE NAME type of the parameter is VARCHAR 12 which limits length to 12 characters st setString 1 Eyjafjallajokull string is longer than type but no exception is raised here set execute executes with no exception and does not find any rows but if an UPDATE is attempted an exception is raised St c prepareStatement UPDATE T SET NAME WHERE ID 10 st setString 1 Eyjafjallajokull string is longe
469. perSQL Server sss 293 D Hypers QL File Links sss irieee EEUU 294 SOL MAS Ee 296 General INGER saioa ea r O ee con nba AE OE E E A 302 ix HyperSQL List of Tables I Available formats of this document iere Ha se Si a Stil l a Dm l Ble pis ea xiii 10 1 TO CHAR TO DATE and TO TIMESTAMP format elements eem 189 12 1 Memory Database URL 2 itr eter he et RE week cet ill E RES NER ROREM Fe AE ER ES 227 12 2 File DSL REIP P 227 12 3 Resource Database URL 1 eror teta rete obo ERR rhe Dl epa kk kite kl va EE Ee pe ip kn ba 227 12 4 Server Database URL iiate citer es eneren koi ue ptik ob ae va kte e SO eu pde m a a a 228 12 5 User and Password 2 exit e rr tek he Xe epe ax Re respuat da rebel ra edet De ku E ol pesa Dro etu E pe e 228 12 6 Column Names m JDBC ResultSet sciri ee iicireineeste eo runet RETENE p kit ee TE ERR pw EEEE Yu gr vb RE ese EENE ve 229 12 7 Creating New Database 5 eee eet eR d klib Ia Rer v au R xo Ua Reda bsbaaas n kok Uu n AREE eA 229 12 8 AutomatiG SBUtdOWN twe ip bete atik tis ai pt 230 12 9 Validity Check Property 45 eerte et rye n ree EE RU Rev ree RESP RERER OUR EE EE EREE EErEE 230 12 10 SOL Keyword Use as Identifiet 1 eoe eno kc tpe Oke sekans ede PRAN ke sige ro o ske per SEDE aepo toe 231 12 11 SQL Keyword Starting with the Underscor
470. pes of callto IDENTITY must be made before any additional update or insert statements are issued by the session In triggers and routines the value returned by the IDENTITY function is correct for the given context For example if a call to a stored procedure inserts a row into a table causing a new identity value to be generated a call to IDENTITY inside the procedure will return the new identity but a call outside the procedure will return the last identity value that was generated before a call was made to the procedure The last inserted IDENTITY value can also be retrieved via JDBC by specifying the Statement or PreparedStatement object to return the generated value The next IDENTITY value to be used can be changed with the following statement Note that this statement is not used in normal operation and is only for special purposes for example resetting the identity generator ALTER TABLE ALTER COLUMN column name RESTART WITH new value m m m For backward compatibility support has been retained for CREATE TABLE lt tablename gt lt colname gt IDENTITY asa shortcut which defines the column both as an IDENTITY column and a PRIMARY KEY column Also for backward compatibility it is possible to use NULL as the value of an IDENTITY column in an INSERT statement and the value will be generated automatically You should avoid these compatibility features as they may be removed from futu
471. plus all authorizations Each database object has a name A name is an identifier and is unique within its name space Schemas and Schema Objects In HyperSQL there is only one catalog per database The name of the catalog is PUBLIC You can rename the catalog with the ALTER CATALOG RENAME TO statement All schemas belong the this catalog The catalog name has no relation to the file name of the database Each database has also an internal unique name which is automatically generated when the database is created This name is used for event logging You can also change this unique name Schema objects are database objects that contain data or govern or perform operations on data By definition each schema object belongs to a specific schema Schema objects can be divided into groups according to their characteristics Some kinds of schema objects can exist independently from other schema object Other kinds can exist only as an element of another schema object These dependent objects are automatically destroyed when the parent object is dropped Separate name spaces exists for different kinds of schema object Some name spaces are shared between two similar kinds of schema objects There can be dependencies between various schema objects as a schema object can include references to other schema objects These references can cross schema boundaries Interdependence and cross referencing between schema objects is allowed in some
472. pper case version The database setting SET DATABASE SQL REGULAR NAMES FALSE can be used to relax the rules for regular identifier With this setting an underscore character can appear at the start of the regular identifier and the dollar sign character can be used in the identifier 49 HyperSGL Schemas and Database Objects A SQL language identifier issimilarto regular identifier but the letters can range only from A Z in the ASCII character set This type of identifier is used for names of CHARACTER SET objects If the character sequence of a delimited identifier is the same as an undelimited identifier it represents the same identifier For example JOHN is the same identifier as JOHN In a regular identifier the case normal form is considered for comparison This form consists of the upper case equivalent of all the letters When a database object is created with one of the CREATE statements or renamed with the ALTER statement if the name is enclosed in double quotes the exact name is used as the case normal form But if it is not enclosed in double quotes the name is converted to uppercase and this uppercase version is stored in the database as the case normal form The character sequence length of all identifiers must be between 1 and 128 characters A reserved word is one that is used by the SQL Standard for special purposes It is similar to a regular identifier butit cannot be used as an identifier
473. predefined character sets These character sets belong to INFORMATION_SCHEMA However when they are referenced in a statement no schema prefix is necessary The following character sets together with some others have been specified by the SQL Standard SQL TEXT SQL IDENTIFIER SQL CHARACTER The SOL CHARACTER consists of ASCII letters digits and the symbols used in the SQL language SOL TEXT and SQL IDENTIFIER are implementation defined HyperSQL defines SQL TEXT as the UNICODE character set and SQL IDENTIFIER as the UNICODE character set minus the SQL language special characters SQL TEXT consists of the full set of Unicode characters These characters can be used in strings and clobs stored in the database The character repertoire of HyperSQL is the UTF16 character set which covers all possible character sets 43 HyperSGL Schemas and Database Objects If a predefined character set is specified for a table column then any string stored in the column must contain only characters from the specified character set HyperSQL does not enforce the CHARACTER SET that is specified for a column and may accept any character string supported by SQL TEXT Collations A COLLATION is the method used for ordering character strings in ordered sets and to determine equivalence of two character strings The system default collation is called SQL TEXT This collation sorts according to the Unicode code of the characters UNICODE SIMPLE Th
474. property is case sensitive Example below jdbc hsqldb file enrolments user aUserName ifexists true 228 HyperSGL Properties Name Default Description password empty password for the user string Standard property This property is case sensitive Example below jdbc hsqldb file enrolments user aUserName password 3xLVz For compatibility with other engines a non standard form of specifying user and password is also supported In this form user name and password appear at the end of the URL string prefixed respectively with the question mark and the ampersand jdbc hsqldb file enrolments create false user aUserName amp password 3xLVz Table 12 6 Column Names in JDBC ResultSet Default Description get_column_name column name in ResultSet This property is used for compatibility with other JDBC driver implementations When true the default ResultSet getColumnName int c returns the underlying column name This property can be specified differently for different connections to the same database The default is true When the property is false the above method returns the same value as ResultSet getColumnLabel int column Example below jdbc hsqldb hsql localhost enrolments get column name false When a ResultSet is used inside a user defined stored procedure the default true is always used for this property Table 12 7 Creating
475. r better operation If you do not want HyperSQL to configure the JDK logging framework you should include the system level property hsqldb reconfig logging false in your environment Server Operation Monitoring A Server or WebServer instance can be started with the property server silent false This causes all the connections and their executed statements to be printed to stdout as the statements are submitted to the server Database Security HyperSQL has extensive security features which are implemented at different levels and covered in different chapters of this guide 1 Theserver can use SSL and IP address access control lists See the HyperSQL Network Listeners Servers chapter 2 You can define a system property to stop the database engine accessing the Java static functions that are on the classpath apart from a limited set that you allow See Securing Access to Classes in the SQL Invoked Routines chapter 3 You can define a system property to allow access to files on the file system outside the database directory and its children This access is only necessary if you use TEXT tables See the Text Tables chapter 4 The database files can be encrypted Discussed in this chapter 5 Within the database the DBA privileges are required for system and maintenance jobs 6 You can define users and roles and grant them access on different database objects Each user has a password and is granted a set of privileges See the Acce
476. r IN id INT OUT firstname VARCHAR 50 OUT lastname VARCHAR 50 READS SQL DATA BEGIN ATOMIC this statement uses the id to get firstname and lastname SELECT first name last name INTO firstname lastname FROM customers WHERE cust id id END Connection conn CallableStatement call conn prepareCall call get customer call setInt 1 121 only the IN or INOUT arguments should be set before the call call execute String firstname call getString 2 the OUT or INOUT arguments are retrieved after the call String lastname call getString 3 SQL JRT procedures are discussed in the Java Language Procedures section below Those routines are called exactly the same way as SQL PSM procedures using the JDBC CallableStatement interface It is also possible to use a JDBC Statement or PreparedStatement object to call a procedure if the procedure arguments are constant If the procedure returns one or more result sets the Statement getMoreResults method should be called before retrieving the ResultSet Java functions are called from JDBC similar to procedures With functions the getMoreResuls method should not be called at all Recursive Routines Routines can be recursive Recursive functions are often functions that return arrays or tables To create a recursive routine the routine definition must be created first with a dummy body Then the ALTER ROUTINE statement is used to define the routine body
477. r PEDE E REI etm gU A RAN da obs che dels estde A Ok pants eects OR e OE 160 Securin S Access 10 Classes nec via aaa ose onn vibe seten sea eesibersveqeuso oc E E EE ones eor potes utens 160 User Defined Aggregate Functions eee mene mee hene hene hhe nere e ense rne 161 Definition of Aggregate Functions esses m eme ee hene hee hene hen rne 161 SQL PSM Aggregate Functions eeeesecseeeeeeeeen eren hene nnne hee thee dte ehe tree then rennen dne 162 Java Aggregate F nCUODS 2 erret niet teneo de vo ton ive ob e kes t a a Sos Dite E e ou tea S RUE 163 Niue 165 uu 165 BEFORE Trig SOTE sc oc adye TM 165 AFTER TAP POTE MH R EEEE 166 INSTEAD OE Trt Gers wiii wal st aksan g ba a nen cases ka kk po a Usa ko a ur dive A e ear EA Y 166 Tigger Properties swe T 166 I rigeer Event see coche ie twa t te toi DEED ip a O dex tete b a a ee A Se n 166 SruEW AM R 166 rip ser Action TIME uuo etd eds tetti ee tec buche alates etu sur ese re saa 166 References to ROWS merereise ped antrene eee end Urt ores seye epast tie ayi de E O san pote ak 167 Trip Per Condition o tisi koka e o aka ke a ta E OE um SES II ex ge DR A n kel gn ESO Ve Dese DUE 167 Trigger Acton I SOL v idee ae setan soe tbsse vere nee bo vekse eee open kk eee De Sk
478. r UPDATE statement the SET NULL option results in the columns of the referencing rows to be set to NULL Similarly the SET DE in the columns of the referencing rows to be set to their default values CHECK check constraint definition FAULT option results check constraint definition CHECK left paren search condition right paren A CHECK constraint can exist for a TABLE or for a DOMAIN The search condition evaluates to an SQL BOOLEAN value for each row of the table Within the search condition all columns of the table row can be referenced For all rows of the table the search condition evaluates to TRUE or UNKNOWN When a new row is inserted or an existing row is updated the search condition is evaluated and if it is FALSE the insert or update fails A CHECK constraint for a DOMAIN is similar In its search condition the term VALUE is used to represents the value to which the DOMAIN applies CREATE TABLE t a VARCHAR 20 CHECK a IS NOT NULL AND CHARACTER LENGTH a 2 The search condition of a CHECK constraint cannot contain any function that is not deterministic A check constraint is a data integrity constraint therefore it must hold with respect to the rest of the data in the database It cannot use values that are temporal or ephemeral For example CURRENT USER is a function that returns different values depending on who is using the database or CURRENT DAT
479. r any security flaws before inclusion in the classpath The default settings do not allow a user to access files outside the database directory This access is for TEXT table source files You can override this programatically or with a system property when you start a server The encryption of database file does not utilise any user supplied information for encryption keys This level of security is outside the realm of users and passwords The first user for a new database has the DBA role This user name need was always SA in older versions of HSQLDB but not in the latest versions The name of the first DBA user and its password can be specified when the database is created by the first connection to the database These settings are then stored in the database The initial user with the DBA role should be used for admin purposes only At least one additional role should be created for normal database use in the application and at least one additional user should be created and granted this role The new role should not be given the DBA role It can be given the CREATE SCHEMA role which allows it to create and access multiple schemas Alternatively the user with the DBA role can create the schemas and their objects and then grant specific privileges on the objects to the non DBA role Authentication Control Authentication is the mechanism that determines if a user can access the database at all Once authentication is performed the authorizati
480. r databases which had the property hsqldb enforce_strict_size false are converted to version 2 0 this property is retained However this is a temporary measure You should test your application to ensure the length precision and scale that is used for column definitions is appropriate for the application data You can test with the default database setting which enforces the sizes String types including all BIT BINARY and CHAR string types plus CLOB and BLOB are generally defined with a length If no length is specified for BIT BINARY and CHAR the default length is 1 For CLOB and BLOB an implementation defined length of 1M is used TIME and TIMESTAMP types can be defined with a fractional second precision between 0 and 9 INTERVAL type definition may have precision and in some cases fraction second precision DECIMAL and NUMERIC types may be defined with precision and scale For all of these types a default precision or scale value is used if one is not specified The default scale is 0 The default fractional precision for TIME is 0 while it is 6 for TIMESTAMP Values can be converted from one type to another in two different ways by using explicit CAST expression or by implicit conversion used in assignment comparison and aggregation String values cannot be assigned to VARCHAR columns if they are longer than the defined type length For CHARACTER columns a long string can be assigned with truncation only if all the characters after
481. r names SET DATABASE SQL REFERENCES set database sql references statement ll a GI lt set database sql references statement gt FALSE ET DATABASE SQL REFERENCES TRU This command can enable or disable full enforcement of the rule that prevents ambiguous column references in SQL statements usually SELECT statements A column reference is ambiguous when it is not qualified by a table name or table alias and can refer to more than one column in a JOIN list The property is FALSE by default SQL Standard requires enforcement It is better to enable this check in order to improve the quality and correctness of SQL statements When false the first matching table is used to resolve the column reference Only a user with the DBA role can execute this statement This is equivalent to the connection property sql enforce refs SET DATABASE SQL TYPES set database sql types statement set database sql types statement SET DATABASE SQL TYPES TRUE FALSE This command can enable or disable full enforcement of the rules that prevents illegal type conversions and parameters or nulls without type in SQL statements usually SELECT statements For example an INTEGER column or a DATE column cannot be compared to a character string or searched with a LIKE expression when the property is TRUE The property is FALSE by default SQL Standard requires enforcement It i
482. r s keystore keytool export keystore server store alias existing alias file server cer In this example server cer is the X509 certificate that you need for the next step Now you need to add this cert to one of the system trust keystores or to a keystore of your own See the Customizing Stores section in JSSERefGuide html http java sun com javase 6 docs technotes guides security jsse JSSERefGuide html CustomizingStores to see where your system trust keystores are You can put private keystores anywhere you want to The following command will add the cert to an existing keystore or create a new keystore if client store doesn t exist Example 13 2 Adding a certificate to the client keystore keytool import trustcacerts keystore trust store alias new_alias file server cer If you are making a new keystore you probably want to start with a copy of your system default keystore which you can find somewhere under your JAVA HOME directory typically jre lib security cacerts fora JDK but I forget exactly where it is for a JRE Unless your OS can t stop other people from writing to your files you probably do not want to set a password on the trust keystore If you added the cert to a system trust store then you are finished Otherwise you will need to specify your custom trust keystore to your client program The generic way to set the trust keystore is to set the system property javax net ssl trustStore every ti
483. r shutdown of the database all the changed data is stored A checkpoint or shutdown still rewrites the script file and saves the backup file according to the other settings sET FILES LOG TRUE FALSE Table 12 48 Automatic Checkpoint Frequency Name Default Description hsqldb log_size size of log when checkpoint is performed The value is the size in megabytes that the 10g file can reach before an automatic checkpoint occurs A checkpoint rewrites the script file and clears the log file SET FILES LOG SIZE lt numeric value gt Table 12 49 Automatic Defrag at Checkpoint Name Description hsqldb defrag_limit percentage of unused space causing a defrag at checkpoint When a checkpoint is performed the percentage of wasted space in the data file is calculated If the wasted space is above the specified limit a defrag operation is performed The default is 0 which means no automatic checkpoint The numeric value must be between 0 and 100 and is interpreted as a percentage of the current size of the data file SET FILES DEFRAG numeric value gt Table 12 50 Logging Data Change Statements Frequency Name Default Description hsqldb write delay write delay for writing and performing sync of log file entries If the property is true the default WRITE DELAY property of the database is used which is 500 milliseconds If the property is f
484. r than type but no exception is raised here st execute exception is thrown when HyperSQL checks the value for update All of the above also applies to setting the values in new and updated rows in updatable ResultSet objects JDBC parameters can be set with any compatible type as supported by the JDBC specification For CLOB and BLOB types you can use streams or create instances of BLOB or CLOB before assigning them to the parameters You can even use CLOB or BLOB objects returned from connections to other RDBMS servers The Connection createBlob and createClob methods can be used to create the new LOBs For very large LOB s the stream methods are preferable as they use less memory For array parameters you must use a java sql Array object that contains the array elements before assigning to JDBC parameters The Connection createArrayOf methodcan be used to create a new object or you can use an Array returned from connections to other RDBMS servers JDBC and Data Change Statements Data change statements also called data manipulation statements DML such as INSERT UPDATE MERGE can be called with different executeUpdate methods of java sql Statement and java sql PreparedStatement Some of these methods allow you to specify how values for generated columns of the table are returned These methods are documented in the JavaDoc for org hsqldb jdbc JDBCStatement and org hsqldb jdbc JDBCPreparedStatement HyperSQL can return no
485. r without time zone The time zone displacement is the time zone of the JDBC session 19 HyperSGL SQL Language When datetime values are retrieved from the database using the ResultSet interface there are two representations The getString methods of the ResultSet interface return an exact representation of the value in the SQL type as it is stored in the database This includes the correct number of digits for the fractional second field and for values with time zone displacement the time zone displacement Therefore if TIME 12 00 00 is stored in the database all users in different time zones will get 12 00 00 when they retrieve the value as a string The get Time and getTimestamp methods of the ResultSet interface return Java objects that are corrected for the session time zone The UTC millisecond value contained the java sql Time or java sql Timestamp objects will be adjusted to the time zone of the session therefore the toString method of these objects return the same values in different time zones If you want to store and retrieve UTC values that are independent of any session s time zone you can use a TIMESTAMP WITH TIME ZONE column The setTime and setTimestamp methods of the PreparedStatement interface which have a Calendar parameter can be used to assign the values The time zone of the given Calendar argument is used as the time zone Conversely the getTime and getTimestamp methods o
486. rSGL Sessions and Transactions Example 3 4 Locking Tables LOCK TABLE table a WRITE table b READ SAVEPOINT savepoint statement savepoint statement SAVEPOINT savepoint specifier savepoint specifier gt savepoint name gt Establish a savepoint This command is used during an SQL transaction It establishes a milestone for the current transaction The SAVEPOINT can be used at a later point in the transaction to rollback the transaction to the milestone RELEASE SAVEPOINT release savepoint statement D release savepoint statement RELEASE SAVEPOINT savepoint specifier Destroy a savepoint This command is rarely used as it is not very useful It removes a SAVEPOINT that has already been defined COMMIT commit statement commit statement COMMIT WORK AND NO CHAIN Terminate the current SQL transaction with commit This make all the changes to the database permanent ROLLBACK rollback statement rollback statement ROLLBACK WORK AND NO CHAIN Rollback the current SQL transaction and terminate it The statement rolls back all the actions performed during the transaction If NO CHAIN is specified a new SQL transaction is started just after the rollback The new transaction inherits the properties of the old transaction ROLLBACK TO SAVEPOINT rollback statement rollback statement ROLLBACK WORK TO SAVEPOINT savepoint
487. ractional seconds precision right paren single datetime field non second primary datetime field left paren interval leading field precision right paren SECOND left paren interval leading field precision comma interval fractional seconds precision right paren primary datetime field non second primary datetime field SECOND non second primary datetime field YEAR MONTH DAY HOUR MINUTE interval fractional seconds precision unsigned integer interval leading field precision unsigned integer Examples of INTERVAL type definition INTERVAL YEAR TO MONTH 20 HyperSGL SQL Language INTERVAL YEAR 3 INTERVAL DAY 4 TO HOUR INTERVAL MINUTE 4 TO SECOND 6 INTERVAL SECOND 4 6 The word INTERVAL indicates the general type name The rest of the definition is called an lt interval qualifier gt This designation is important as in most expressions lt interval qualifier gt is used without the word INTERVAL Interval Values An interval value can be negative positive or zero An interval type has all the datetime fields in the specified range These fields are similar to those in the TIMESTAMP type The differences are as follows The first field of an interval value can hold any numeric value up to the specified precision For example the hour field in HOUR 2 TO SECOND can hold values above
488. rations but can return duplicate rows They are A UNION ALL B A INTERSECT ALL Band A EXCEPT ALL B The UNION ALL operation adds all the rows from A and B into the new table The INTERSECT operation copies only those rows from each table that also exist in the other table If n copies of a rows exists in one table and m copies in the other table the number of copies in the result table is the smaller of n and m The EXCEPT operation copies those rows from the first table which do not exist in the second table If n copies of a row exist in the first table and m copies in the second table the number of copies in the result table is n m or if n m then zero With Clause and Recursive Queries The optional WITH clause can be used in a query expression The WITH clause lists one or more named ephemeral tables that can be referenced in the query expression body The ephemeral tables are created and populated before 128 HyperSGL Data Access and Change the rest of the query expression is executed Their contents do not change during the execution of the query expression body with clause WITH RECURSIVE with list with list with list element comma with list element with list element query name left paren with column list right paren AS left paren query expression right paren with column list column name list
489. re versions of HyperSQL In the following example the identity value for the first INSERT statement is generated automatically using the DEFAULT keyword The second INSERT statement uses a call to the IDENTITYO function to populate a row in the child table with the generated identity value CREATE TABLE star id INTEGER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY firstname VARCHAR 20 lastname VARCHAR 20 CREATE TABLE movies starid INTEGER movieid INTEGER PRIMARY KEY title VARCHAR 40 INSERT INTO star id firstname lastname VALUES DEFAULT Felix the Cat INSERT INTO movies starid movieid title VALUES IDENTITY 10 Felix in Hollywood HyperSQL 2 1 also supports IDENTITY columns that use an external named SEQUENCE object This feature is not part of the SQL Standard The example below uses this type of IDENTITY Note the use of CURRENT VALUE FOR seq here is multi session safe The returned value is the last value used by this session when the row was inserted into the star table This value is available until the transaction is committed After commit NULL is returned by the CURRENT VALUE FOR expression until the SEQUENCE is used again CREATE SEQUENCE seq CREATE TABLE star id INTEGER GENERATED BY DEFAULT AS SEQUENCE seq PRIMARY KEY firstname VARCHAR 20 lastname VARCHAR 20 CREATE TABLE movies starid INTEGER movieid INTEGER PRIMARY KEY title VARCHAR 40 INSERT INTO star id firs
490. reasons there may be some compatibility issues when converting old database or using applications that were written 273 HyperSQL Deployment Guide for version 1 8 x or earlier Some of the potential issues and enhancements are listed here See the full list of connection properties for alternatives By default when comparison strings the shorter string is padded with spaces This has an effect on comparing test and test which are now considered equal despite the length difference This behaviour is controlled by the default PAD SPACE property of collations which can be changed to NO PAD See the statement SET DATABASE COLLATION lt name gt PAD SPACE NO PAD T e User names and passwords are case sensitive Check the script file of a database for the correct case of user name and password and use this form in the connection properties or on connection URL It is now possible to specify the admin username and password for a new database instead of SA and the empty password e HyperSQL 2 0 has several settings that relax its conformance to the SQL Standard in the areas of type conversion and object names These settings can be turned on for maximum conformance Check constraints must conform to the SQL Standard A check constraint is rejected if it is not deterministic or retrospectively deterministic When opening an old database HyperSQL silently drops check constraints that no longer compile See u
491. regate functions are discussed in chapters that cover SQL in general The built in functions fall into three groups e SQL Standard Functions A wide rang of functions defined by SQL Foundation are supported SQL Foundation functions that have no parameter are called without empty parentheses Functions with multiple parameters often use keywords instead of commas to separate the parameters Many functions are overloaded Among these some have one or more optional parameters that can be omitted while the return type of some functions is dependent upon the type of one of the parameters The usage of SQL Standard Functions where they can be used is covered more extensively in the Data Access and Change chapter JDBC Open Group CLI Functions These functions were defined as an extension to the CLI standard which is the basis for ODBC and JDBC and supported by many database products JDBC supports an escape mechanism to specify function calls in SQL statements in a manner that is independent of the function names supported by the target database engine For example SELECT fn DAYOFMONTH dateColumn FROM myTable can be used in JDBC and is translated to Standard SQL as SELECT EXTRACT DAY_OF_MONTH FROM dateColumn FROM myTable if a database engine supports the Standard syntax If a database engine does not support Standard SQL then the translation will be different HyperSQL supports all the function names specified in the JDBC specifications as nat
492. rences preceding the current table reference lt collection derived table gt UNNEST lt left paren gt lt array value expression gt lt right paren gt WITH ORDINALITY The lt array value expression gt can be the result of a function call If the arguments of the function call are values from the tables on the left of the UNNEST then the function is called for each row of table In the first example below UNNEST is used with the built in function SEQUENCE_ARRAY to build a table containing dates for the last seven days and their ordinal position In the second example a select statement returns costs for the last seven days In the third example the WITH clause turns the two selects into named subqueries which are used in a SELECT statement that uses a LEFT join SELECT FROM UNNEST SEQUENCE ARRAY CURRENT DATE 7 DAY CURRENT DATE 1 DAY 1 DAY WITH ORDINALITY AS T D L D J AO MOS OMe 2010 07 26 ZOOS OM 24 2010 09 2 8 ROMO 2E Or am CO BO E 123 HyperSGL Data Access and Change ZO AOS OSM AOMOO YS 7 CREATE TABLE expenses item date DATE cost DECIMAL 8 2 SELECT item_date SUM cost AS s FROM expenses WHERE item_date gt CURRENT_DATE 7 DAY GROUP BY item_date ITEM DATE S BANN ton A 010 225 SOG AS WITH costs i d s AS SELECT item date SUM cost AS s FROM expenses WHERE item date gt CURRENT DATE 7 DAY GROUP BY item date dates d i AS SELECT FROM
493. rently only simple distinct types can be defined without further attributes CREATE CAST user defined cast definition D user defined cast definition CREATE CAST left paren source data type AS target data type right paren WITH cast function AS ASSIGNMENT cast function specific routine designator gt source data type data type target data type data type Define a user defined cast This feature may be supported in a future versions of HyperSQL DROP CAST 71 HyperSGL Schemas and Database Objects drop user defined cast statement drop user defined cast statement DROP CAST left paren source data type AS target data type right paren drop behavior Destroy a user defined cast This feature may be supported in a future versions of HyperSQL CREATE CHARACTER SET character set definition character set definition CREATE CHARACTER SET character set name AS character set source collate clause character set source GET character set specification Define a character set A new CHARACTER SET is based on an existing CHARACTER SET The optional collate clause specifies the collation to be used otherwise the collation is inherited from the default collation for the source CHARACTER SET Currently this statement has no effect as the character set used by HSQLDB is Unicode a
494. ring value function string value function Specify a function that returns a character string or binary string The supported character value functions are listed and described in the Built In Functions chapter datetime value expression datetime value expression datetime valu xpression datetime term interval value expression plus sign datetime term datetime valu xpression plus sign interval term datetime valu xpression minus sign interval term datetime term datetime factor datetime factor datetime primary time zone datetime primary value expression primary lt datetime value function time zone AT time zone specifier gt time zone specifier gt LOCAL TIME ZONE lt interval primary gt Specify a datetime value Details are described in the SQL Language chapter datetime value function datetime value function lt datetime value function Specify a function that returns a datetime value The supported datetime value functions are listed and described in the Built In Functions chapter 109 HyperSGL Data Access and Change interval term interval value expression interval value expression interval term interval value expression 1 plus sign interval term 1 interval value expression 1 minus sign interval term 1 lef
495. rison predicate comparison predicate row value predicand gt comp op row value predicand gt comp op equals operator not equals operator less than operator greater than operator less than or equals operator greater than or equals operator Specify a comparison of two row values If either row value predicand evaluates to NULL the result of comparison predicate is UNKNOWN Otherwise the result is TRUE FALSE or UNKNOWN If the degree of row value predicand is larger than one comparison is performed between each field and the corresponding field in the other row value predicand from left to right one by one When comparing two elements if either field is NULL then the result is UNKNOWN For equals operator if the result of comparison is TRUE for all field the result of the predicate is TRUE If the result of comparison is FALSE for one field the result of predicate is FALSE Otherwise the resultis UNKNOWN The not equals operator is translated to NOT row value predicand row value predicand The less than or equals operator istranslated to row value predicand gt row value predicand OR row value predicand gt lt row value predicand The greater than or equals operator is translated similarly For the less than operator and greater than operator gt if two fields at a given position are equal then comparison co
496. role statement drop role statement DROP ROLE role name Drop destroy a role If the specified role is the authorization for a schema the schema is destroyed Only a user with the DBA role can execute this statement GRANTED BY grantor determination GRANTED BY grantor lt grantor gt CURRENT USER CURRENT ROLE The authorization that is granting or revoking a role or privileges The optional GRANTED BY lt grantor gt clause can be used in various statements that perform GRANT or REVOKE actions If the clause is not used the authorization is CURRENT_USER Otherwise it is the specified authorization GRANT grant privilege statement lt grant privilege statement gt GRANT lt privileges gt TO lt grantee gt lt comma gt lt grantee gt WITH GRANT OPTION GRANTED BY lt grantor gt Assign privileges on schema objects to roles or users Each grantee is a role or a user If WITH GRANT OPTION is specified then the grantee can assign the privileges to other grantee objects privileges object privileges ON object name gt lt object name gt i TABLE lt table name gt DOMAIN lt domain name gt COLLATION lt collation name gt CHARACTER SET lt character set name gt TRANSLATION lt transliteration name gt TYPE lt user defined type name gt SEQUENCE lt sequence generator name gt lt specific rout
497. roperties p server setLogWriter null server setErrWriter null server start can use custom writer l can use custom writer The Server object has several alternative methods for setting databases and their public names The server should be shutdown using the shutdown method Allowing a Connection to Open or Create a Database If the server remote open property is true the Server works differently from the normal mode In this mode it is not necessary to have any databases listed as server database O etc in the Server startup properties If there are databases listed they are opened as normal The server does not shutdown when the last database is closed In this mode a connection can be established to a database that is not open or does not exist The server will open the database or create it then return a connection to the database The connection URL must include the path to the database separated with a semicolon from the alias In the example below the database path specified as file C files mydatabase is opened and the database alias xdb is assigned to the database After this the next connection to the specified alias will connect to the same database The database path can also point to a mem database If you use database properties on the URL these properties are used when the new database is created If no database properties are used on the URL you can also specify the path with filepath lt pa
498. rrent row of the result set to delete the row The procedure updates the val p argument and when it returns the val p represents the total count of rows with the given lastname before the duplicates were deleted CREATE PROCEDURE test proc INOUT val p INT IN lastname p VARCHAR 20 MODIFIES SQL DATA BEGIN ATOMIC SET val p 0 for label FOR SELECT FROM customer WHERE lastname lastname p DO IF val p 0 THEN DELETE FROM customer WHERE customer id id END IF SET val p val p 1 END FOR for label END Conditional Statements There are two types of CASE WHEN statement and the IF THEN statement CASE WHEN case when statement 150 HyperSQL SQL Invoked Routines The simple case statement uses a case operand as the predicand of one or more predicates For the right part of each predicate it specifies one or more SQL statements to execute if the predicate evaluates TRUE If the ELSE clause is not specified at least one of the search conditions must be true otherwise an exception is raised simple case statement gt CASE case operand gt simple case statement when clause case statement else clause END CASE simpl cas statement when clause WHEN when operand list THEN SOL statement list lt case statement else clause gt ELSE lt SQL statement list gt A skeletal example is given below The variable var one is first
499. rver properties or webserver properties then verify that you can run Sq1Tool as root to connect to the catalogs with these urlids For the latter test use the rcfile switch if you are setting AUTH FILE in the init script config file If your database really is not starting then verify that you can su to the database owner account and start the database The command su USERNAME c won t work on most UNIXes unless the target user has a real login shell Therefore if you try to tighten up security by disabling this user s login shell you will break the init script If these possibilities don t pan out then debug the init script or seek help as described below To debug the init script run it in verbose mode to see exactly what is happening and perhaps manually run the steps that are suspect To run an init script in fact any sh shell script in verbose mode use sh with the x or v switch like sh x path to hsaoldb start See the man page for sh if you don t know the difference between v and x If you want troubleshooting help use the HSQLDB lists forums Make sure to include the revision number from your hsqldb init script it s towards the top in the line that starts like Id and the output of a run of 264 HyperSGL HyperSQL on UNIX sh x path to hsqldb start gt tmp hstart log 2 gt amp 1 Upgrading This section is for users who are using our UNIX init script and who are
500. rypted not the memory image Poking into computer memory while the database is open will expose the contents of the database HyperSQL is open source Someone who has the key can compile and use a modified version of the program that saves a full cleartext dump of an encrypted database Therefore encryption is generally effective only when the users who have access to the crypt key are trusted Monitoring Database Operations Database operations can be monitored at different levels using internal HyperSQL capabilities or add ons External Statement Level Monitoring Statement level monitoring allows you to gather statistics about executed statements HyperSQL is supported by the monitoring tool JAMon Java Application Monitor JAMon is currently developed as the SourceForge project jamonapi JAMon works at the JDBC level It can monitor and gather statistics on different types of executed statements or other JDBC calls Early versions of JAMon were developed with HSQLDB and had to be integrated into HSQLDB at code level The latest versions can be added on as a proxy in a much simpler fashion Internal Statement Level Monitoring The internally generated individual sql log for the database can be enabled with the SET DATABASE EVENT LOG SQL LEVEL statement described in this chapter As all the executed statements are logged there is an impact on speed So you should only use this for debugging Two levels of sql loggi
501. s a type A DOMAIN is based ona predefined type which is a base type defined by the Standard It can have a default clause similar to a column default clause It can also have one or more CHECK constraints which limit the values that can be assigned to a column or variable that has the DOMAIN as its type CREATE DOMAIN valid string AS VARCHAR 20 DEFAULT NO VALUE CHECK value IS NOT NULL AND CHARACTER LENGTH value 2 63 HyperSGL Schemas and Database Objects ALTER DOMAIN alter domain statement alter domain statement ALTER DOMAIN domain name alter domain action alter domain action set domain default clause drop domain default clause add domain constraint definition drop domain constraint definition Change a domain and its definition SET DEFAULT set domain default clause set domain default clause SET default clause Set the default value in a domain DROP DEFAULT drop domain default clause drop domain default clause DROP DEFAULT Remove the default clause of a domain ADD CONSTRAINT add domain constraint definition add domain constraint definition ADD domain constraint Add a constraint to a domain DROP CONSTRAINT drop domain constraint definition drop domain constraint definition DROP CONSTRAINT constraint name Destroy a constraint on a domain If the drop behavior is CASCADE
502. s Guide if you don t understand this AUTH FILE home blaine sqltool rc Typical users will leave this unset and it will default to org hsqldb server Server If you need to run the HSQLDB WebServer class instead due to a firewall or routing impediment set this to org hsqldb server WebServer see the docs about running WebServr and set up a webserver properties file instead of a server properties The JVM that is started can invoke many classes see the following item about that but this is the server that is used 1 to check status 2 to shut down the JVM TARGET CLASS org hsqldb server WebServer This is where you may specify both command line parameters to TARGET CLASS plus any number of additional progams to run along with their command line parameters The MainInvoker program is used to embed these multiple static main invocations into a single JVM so see the API spec for org hsqldb util MainInvoker if you want to learn more N b You should only use this setting to set HSQLDB Server or WebServer parameters if you run multiple instances of this class since you can use the server webserver properties file for a single instance Every additional class in addition to the TARGET CLASS must be preceded with an empty string so that MainInvoker will know you are giving a class name MainInvoker will invoke the normal static main String method of each such class FE Se SE SE SR db db FE SE db SE
503. s a before and after state for each row For UPDATE triggers both before and after states exist representing the row before the update and after the update For DELETE triggers there is only a before state For INSERT triggers there is only an after state If a triggeris FOR EACH STATEMENT then a transient table is created containing all the rows for the before state and another transient table is created for the after state The REFERENCING transition table or variable isusedto give a name to the before and after data row or table This name can be referenced in the SQL procedure statement to access the data The optional triggered when clause isa search condition similar to the search condition of a DELETE or UPDATE statement If the search condition is not TRUE for a row then the trigger is not activated for that row 65 HyperSGL Schemas and Database Objects The SQL procedure statement is limited to INSERT DELETE UPDATE and MERGE statements The HSQLDB trigger class FON is a delimited identifier that contains the fully qualified name of a Java class that implements the org hsqldb Trigger interface Early releases of HyperSQL version 2 0 do not allow the use of OLD TABLE or NEW TABLE in statement level trigger definitions DROP TRIGGER drop trigger statement drop trigger statement DROP TRIGGER trigger name Destroy a trigger Routine Creation schema
504. s better to enable this check in order to improve the quality and correctness of SQL statements Only a user with the DBA role can execute this statement This is equivalent to the connection property sql enforce type SET DATABASE SQL TDC DELETE 215 HyperSGL System Management set database sql tdc delete statement set database sql tdc delete statement SET DATABASE SQL TDC DELETE TRUE FALSE This command can enable or disable full enforcement of the SQL Standard rules that prevents triggered data change exceptions caused by ON DELETE CASCADE clauses of foreign key constraint When there are multiple constraints a row may be updated by one constraint and deleted by another constraint in the same operation This is not allowed by default Changing this to false allows such violations of the Standard to pass without an exception The property is TRUE by default SQL Standard requires enforcement therefore this property shouldn t be changed unless an application written for a non conforming RDBMS needs it Only a user with the DBA role can execute this statement This is equivalent to the connection property sql enforce tdc delete SET DATABASE SQL TDC UPDATE set database sql tdc update statement set database sql tdc update statement SET DATABASE SQL TDC UPDATE TRUE FALSE This command can enable or disable full enforcement of the SQL Standard rules
505. s over Java Language Routines SQL JRT and a couple of disadvantages SQL language routines PSM do not rely on custom Java classes to be present on the classpath The databases that use them are therefore more portable e For a routine that accesses SQL DATA all the SQL statements in an SQL routine are known and monitored by the engine The engine will not allow a table routine or sequence that is referenced in an SQL routine to be dropped or its structure modified in a way that will break the routine execution The engine does not keep this information about a Java routine 143 HyperSQL SQL Invoked Routines Because the statements in an SQL routine are known to the engine the execution of an SQL routine locks all the database objects it needs to access before the actual execution With Java routines locks are obtained during execution and this may cause additional delays in multi threaded access to the database e For routines that do not access SQL DATA Java routines SQL JRT may be faster if they perform extensive calculations Only Java routines can access external programs and resources directly Routine Statements The following SQL Statements can be used only in routines These statements are covered in this section lt handler declaration gt lt table variable declaration gt lt variable declaration gt lt declare cursor gt lt assignment statement gt lt compound statement gt lt case st
506. s separately on each different signature of the routine Each grantee is the name of a role or a user Examples of GRANT statement are given below GRANT ALL ON SEQUENCE aSequence TO roleOrUser GRANT SELECT ON aTable TO roleOrUser GRANT SELECT UPDATE ON aTABLE TO roleOrUserl roleOrUser2 GRANT SELECT columnA columnB UPDATE columnA columnB ON TABLE aTable TO roleOrUser GRANT EXECUTE ON SPECIFIC ROUTINE aroutine 1234 TO rolOrUser As mentioned in the general discussion it is better to define a role for the collection of all the privileges required by an application This role is then granted to any user If further changes are made to the privileges of this role they are automatically reflected in all the users that have the role GRANT grant role statement grant role statement GRANT role name comma role name Jj TO lt grantee gt comma grantee WITH ADMIN OPTION GRANTED BY lt grantor gt Assign roles to roles or users One or more roles can be assigned to one or more grantee objects A grantee is a user or arole If the WITH ADMIN OPTION is specified then each grantee can grant the newly assigned roles to other grantees An example of user and role creation with grants is given below CREATE USER appuser CREATE ROLE approle GRANT approle TO appuser GRANT SELECT UPDATE ON TABLE atable TO approle GRANT USAGE ON SEQUENCE asequence to approle
507. s stored in the database as MEMORY tables Therefore the amount of JVM memory should be increased when more than tens of thousands of LOBs are stored in the database If your database contains more than a few hundreds of thousands of LOBs and memory use becomes an issue you can change one or all LOB schema tables to CACHED tables See statements below Example 11 1 Using CACHED tables for the LOB schema SET TABLE SYSTEM LOBS BLOCKS TYPE CACHED SET TABLE SYSTEM LOBS LOBS TYPE CACHED SET TABLE SYSTEM LOBS LOB IDS TYPE CACHED Deployment context The files used for storing HyperSQL database data are all in the same directory New files are always created and deleted by the database engine Two simple principles must be observed The Java process running HyperSQL must have full privileges on the directory where the files are stored This include create and delete privileges e The file system must have enough spare room both for the permanent and temporary files The default maximum size of the log file is SOMB The data file can grow to up to 16GB more if the default has been increased 199 HyperSGL System Management The backup file can be up to the size of the data file The lobs file can grow to several terabytes The temporary files created at the time of a SHUTDOWN can be equal in size to the script file and the data file Readonly Databases A file catalog can be made readonly permanently or it
508. saction Rollback in Deadlock Name Description effect of deadlock or other conflicts on transaction hsqldb tx_conflict_rollback When a transaction deadlock or other unresolvable conflict is about to happen the current transaction is rolled back and an exception is raised When this property is set false the transaction is not rolled back Only the latest action that would cause the conflict is undone and an error is returned The property should not be changed unless the application can quickly perform an alternative statement and complete the transaction It is provided for compatibility with other database engines which do not roll back the transaction upon deadlock SET DATABASE TRANSACTION ROLLBACK ON CONFLICT TRUE FALSE Table 12 33 Time Zone and Interval Types Name Default Description hsqldb translate_tti_types usage of type codes for advanced datetime and interval types 235 HyperSGL Properties Name Default Description If the property is true the TIME TIMESTAMP WITH TIME ZONE types and INTERVAL types are represented in JDBC methods of ResultSetMetaData and DatabaseMetaData as JDBC datetime types without time zone and the VARCHAR type respectively The original type names are preserved SET DATABASE SQL TRANSLATE TTI TYPES TRUE FALSE Database File and Memory Properties Table 12 34 Opening Database as Read Only Name Description readonly reado
509. same directory as the init script As long as these two files reside in Library StartupItems hsqldb your init script is active for portability reasons it doesn t check for a setting in etc hostconfig You can run it as a Startup Item by running SystemStarter start stop restart Hsqldb Hsqldb is the service name See the man page for SystemStarter To disable the init script wipe out the Library StartupItems hsqldb directory Hard to believe but the Mac people tell me that during system shutdown the Startup Items don t run at all Therefore if you don t want your data corrupted make sure to run SystemStarter stop Hsqldb before shutting down your Mac Follow the examples in the config file to add additional classes to the server JVM s classpath and to execute additional classes in your JVM See the SERVER_ADDL_CLASSPATH and INVOC_ADDL_ARGS items Troubleshooting the Init Script Definitely look at the init script log file which is at an OS sependent location but is usually at var log hsqldb log Do a ps to look for processes containing the string hsqldb and try to connect to the database from any client If the init script starts up your database successfully but incorrectly reports that it has not then your problem is with specification of urlid s or SqITool setup If your database really did not start then skip to the next paragraph Verify that your config file assigns a urlid for each catalog defined in se
510. se Objects create index statement create index statement CREATE INDEX index name ON table name left paren column name ASC DESC right paren Creates an index on a group of columns of a table The optional ASC DESC specifies if the column is indexed in the ascending or descending order but has no effect on how the index is created it is allowed for compatibility with other database engines HyperSQL can use all indexes in ascending or descending order as needed Indexes should not duplicate the columns of PRIMARY KEY UNIQUE or FOREIGN key constraints as each of these constraints creates an index automatically DROP INDEX drop index statement drop index statement DROP INDEX IF EXISTS index name IF EXISTS Destroy an index ALTER INDEX change the columns of an index alter index statement ALTER INDEX index name left paren column name right paren Redefine an index with a new column list This statement is more efficient than dropping an existing index and creating anew one CREATE TYPE user defined type definition user defined type definition CREATE TYPE user defined type body user defined type body schema resolved user defined type name gt AS representation lt representation gt predefined type Define a user defined type Cur
511. sed Note that all other types accept a declaration without a size which is interpreted as a default size SET DATABASE SQL SIZE TRUE FALSE Table 12 14 Type Enforcement in Comparison and Assignment Name Default Description sql enforce types enforcing type compatibility This property when set true causes an error when an SQL statements contains comparisons or assignments that are non standard due to type mismatch Most illegal comparisons and assignments will cause an exception regardless of this setting This setting applies to a small number of comparisons and assignments that are possible but not standard conformant and were allowed in previous versions of HSQLDB 231 HyperSGL Properties Name Default Description SET DATABASE SQL TYPES TRUE FALSE Table 12 15 Foreign Key Triggered Data Change Name Default Description sql enforce tdc delete enforcing triggered data change violation for deletes The ON DELETE and ON UPDATE clauses of constraints cause data changes in rows in different tables or the same table When there are multiple constraints a row may be updated by one constraint and deleted by another constraint in the same operation This is not allowed by default Changing this property to false allows such violations of the Standard to pass without an exception Used for porting from database engines that do not enforce the constraints S
512. sed when the column values are based on a named SEQUENCE object which must already exist Example below CREATE TABLE t id INTEGER GENERATED BY DEFAULT AS SEQUENCE s name VARCHAR 20 PRIMARY KEY Inserting rows is done in the same way for a named or unnamed sequence generator In both cases if no value is specified to be inserted or the DEFAULT keyword is used for the column the value is generated by the sequence generator If a value is specified this value is used if the column definition has the BY DEFAULT specification If the column definition has the ALWAYS specification a value can be specified but the OVERRIDING SYSTEM VALUES must be specified in the INSERT statement The other way in which the column value is autogenerated is by using the values of other columns in the same row This method is often used to create an index on a value that is derived from other column values generation clause GENERATED ALWAYS AS generation expression generation expression left paren value expression right paren The generation clause is used for special columns which represent values based on the values held in other columns in the same row The value expression must reference only other non generated columns of the table in the same row Any function used in the expression must be deterministic and must not access SQL data No query expression is allowed When generation clause
513. ser defined functions and procedures including aggregate functions An aggregate function can return an array that contains all the scalar values that have been aggregated These capabilities allow a wider range of applications to be covered by user defined functions and easier data exchange between the engine and the user s application Indexes and Query Speed HyperSQL supports PRIMARY KEY UNIQUE and FOREIGN KEY constraints which can span multiple columns The engine creates indexes internally to support PRIMARY KEY UNIQUE and FOREIGN KEY constraints a unique index is created for each PRIMARY KEY or UNIQUE constraint an ordinary index is created for each FOREIGN KEY constraint HyperSQL allows defining indexes on single or multiple columns You should not create duplicate user defined indexes on the same column sets covered by constraints This would result in unnecessary memory and speed overheads See the discussion in the Deployment Guide chapter for more information Indexes are crucial for adequate query speed When range or equality conditions are used e g SELECT WHERE acol gt 10 AND bcol 0 anindex should exist on one of the columns that has a condition In this example the bcol column is the best candidate HyperSQL always uses the best condition and index If there are two indexes one on acol and another on bcol it will choose the index on bcol Queries always return results whether indexes exist or not but
514. sk Use Memory used by the program can be thought of as two distinct pools memory used for table data which is not released unless the data is deleted and memory that can be released or is released automatically including memory used for caching building result sets and other internal operations such as storing the information needed for a rollback a transaction Most JVM implementations allocate up to a maximum amount of memory usually 64 MB by default This amount is generally not adequate when large memory tables are used or when the average size of rows in cached tables is larger than a few hundred bytes The maximum amount of allocated memory can be set on the Java command line that is used for running HyperSQL For example with Sun JVM parameter Xmx256m increases the amount to 256 MB Table Memory Allocation The memory used fora MEMORY table is the sum of memory used by each row Each MEMORY table row is a Java object that has 2 int or reference variables It contains an array of objects for the fields in the row Each field is an object such as Integer Long St ring etc In addition each index on the table adds a node object to the row Each node object has 6 int or reference variables As a result a table with just one column of type INTEGER will have four objects per row with a total of 10 variables of 4 bytes each currently taking up 80 bytes per row Beyond this each extra column in the table adds at least a few bytes to the si
515. specified by SQL 92 and many enhancements added in later versions of the standard Cursors And Result Sets An SQL statement can executed in two ways One way is to use the java sql Statement interface The Statement object can be reused to execute completely different SQL statements Alternatively a PreparedStatment can be used to execute an SQL statement repeatedly and the statements can be parameterized Using either form if the SQL statement is a query expression a ResultSet is returned In SQL when a query expression SELECT or similar SQL statement is executed an ephemeral table is created When this table is returned to the application program it is returned as a result set which is accessed row by row by a cursor A JDBC ResultSet represents an SQL result set and its cursor The minimal definition of a cursor is a list of rows with a position that can move forward Some cursors also allow the position to move backwards or jump to any position in the list An SQL cursor has several attributes These attributes depend on the query expression Some of these attributes can be overridden by specifying qualifiers in the SQL statement or by specifying values for the parameters of the JDBC Statement or PreparedStatement Columns and Rows The columns of the rows of the result set are determined by the query expression The number of columns and the type and name characteristics of each column are known when the query expression is comp
516. specifier gt Rollback part of the current SQL transaction and continue the transaction The statement rolls back all the actions performed after the specified SAVEPOINT was created The same effect can be achieved with the rollback Savepoint savepoint method of the JDBC Connection object Example 3 5 Rollback perform some inserts deletes etc SAVEPOINT A perform some inserts deletes selects etc ROLLBACK WORK TO SAVEPOINT A 38 HyperSGL Sessions and Transactions all the work after the declaration of SAVEPOINT A is rolled back DISCONNECT disconnect statement lt disconnect statement gt DISCONNECT Terminate the current SQL session Closing a JDBC connection has the same effect as this command SET SESSION CHARACTERISTICS set session characteristics statement lt set session characteristics statement gt SET SESSION CHARACTERISTICS AS lt session characteristic list gt lt session characteristic list gt lt session characteristic gt lt comma gt lt session characteristic gt lt session characteristic gt lt session transaction characteristics gt lt session transaction characteristics gt TRANSACTION lt transaction mode gt comma transaction mode Set one or more characteristics for the current SQL session This command is used to set the transaction mode for the session This endures for all transactions u
517. ss Control chapter 7 You can define a password complexity check function for new and changed passwords This is covered below under Authentication Settings 8 You can use external authentication instead of internally stored password to authenticate users for each database This is covered below under Authentication Settings HyperSQL security is multi layered and avoids any loopholes to circumvent security It is however the user s responsibility to enable the required level of security Security Defaults The default setting are generally adequate for most embedded use of the database or for servers on the host that are accessed from the same machine For servers accessed within a network and especially for those accessed from outside the network additional security settings must be used The default settings for server and web server do not use SSL or IP access control lists These features are enabled programatically or with the properties used to start the server 204 HyperSGL System Management The default settings allow a database user with the DBA role or with schema creation role to access static functions on the classpath You can disable this feature or limit it to specific classes and methods This can be done programatically or by setting a system property when you start a server If access to specific static functions is granted then these functions must be considered as part of the database program and checked fo
518. ssible to insert a row into the table without specifying a value for the column default clause DEFAULT default option default option literal datetime value function USER CURRENT USER CURRENT ROLE SESSION USER SYSTEM USER CURRENT CATALOG CURRENT SCHEMA CURRENT PATH NULL The type of the default option must match the type of the column In PGS PostgreSQL compatibility mode a NEXTV AL function can be used Also in MSS compatibility mode the default value can be enclosed in parentheses CONSTRAINT constraint name and characteristics constraint name definition CONSTRAINT constraint name constraint characteristics constraint check time NOT DEFERRABLE constraint check time constraint check time INITIALLY DEFERRED INITIALLY IMMEDIATE Specify the name of a constraint and its characteristics By default the constraint is NOT DEFERRABLE and INITIALLY IMMEDIATE This means the constraint is enforced as soon as a data change statement is executed If INITIALLY DEFERRED is specified then the constraint is enforced when the session commits The characteristics must be compatible The constraint check time can be changed temporarily for an SQL session HyperSQL does not support deferring constraint enforcement This feature of the SQL Standard has been criticised because it allows a s
519. t If you want a binary package and we either don t provide it or you prefer somebody else s build you should still find out the current version of HyperSQL available at SourceForge It s very likely that you can find a binary package for your UNIX variant with your OS distributor http www jpackage org http sunfreeware com etc Nowadays most UNIXes have software package management systems which check Internet repositories Just search the repositories for hsqldb and hypersql The challenge is to find an up to date package You will get better features and support if you work with the current stable release of HyperSQL In particular HyperSQL version 2 0 0 added tons of new features Pay attention to what JVM versions your binary package supports Our builds version 2 0 and later document the Java version it was built with in the file doc index htm1 but you can t depend on this if somebody else assembled your distribution Java jar files are generally compatible with the same or greater major versions For example if your hsqldb jar was built with Java 1 3 6 11 then it is compatible with Java versions 1 3 and greater Note It could very well happen that some of the file formats which I discuss below are not in fact offered If so then we have not gotten around to building them Binary installation depends on the package format that you downloaded Installing from a pkg Z file This package is only for use by a
520. t SESSION USER is the same as CURRENT USER SYSTEM USER is the user that connected to the database It is not changed with any command until the session is closed CURRENT SCHEMA is default schema of the user or a schema subsequently set by the SET SCHEMA command CURRENT CATALOG is always the same within a given HyperSQL database and indicates the name of the catalog IS AUTOCOMMIT IS AUTOCOMMIT Returns TRUE if the session is in autocommit mode HyperSQL IS READONLY SESSION IS READONLY SESSION Returns TRUE if the session is in read only mode HyperSQL IS READONLY DATABASE IS READONLY DATABASE Returns TRUE if the database is a read only database HyperSQL IS READONLY DATABASE FILES IS READONLY DATABASE FILES Returns TRUE if the database is a read only files database In this kind of database it is possible to modify the data but the changes are not persisted to the database files HyperSQL ISOLATION LEVEL ISOLATION LEVEL 195 HyperSGL Built In Functions Returns the current transaction isolation level for the session Returns either READ COMMITTED or SERIALIZABLE as a string HyperSQL SESSION ID SESSION ID Returns the id of the session as a BIGINT value Each session id is unique during the operational lifetime of the database Id s are restarted after a shutdown and restart HyperSQL SESSION ISOLATION LEVEL SESSION ISOLATI
521. t lt character representation gt lt nonquote character gt lt quote symbol gt lt nonquote character gt any character apart from the quote symbol lt quote symbol gt lt quote gt lt quote gt lt national character string literal gt E N quote character representation quote lt separator gt lt quote gt character representation quote Unicode character string literal lt introducer gt lt character set specification gt U lt ampersand gt lt quote gt Unicode representation quote lt separator gt quote Unicode representation gt quote lt Unicode scape specifier gt lt Unicode representation gt lt character representation gt lt Unicod scape value gt The type of a character literal is CHARACTER The length of the string literal is the character length of the type If the quote character is used in a string it is represented with two quote characters Long literals can be divided into multiple quoted strings separated with a space or end of line character Unicode literals start with U amp and can contain ordinary characters and unicode escapes A unicode escape begins with the backslash X character and is followed by four hexadecimal characters which specify the character code 100 HyperSGL Data Access and Change Example of character literals are given below Lomllirteeg att
522. t lt term gt lt solidus gt lt factor gt lt factor gt lt sign gt lt numeric primary gt lt numeric primary gt lt value expression primary gt lt numeric value function gt Specify a numeric value The BNF indicates that lt asterisk gt and lt solidus gt the operators for multiplication and division have precedence over minus sign and plus sign numeric value function numeric value function numeric value function position expression extract expression length expression 108 HyperSGL Data Access and Change Specify a function yielding a value of type numeric The supported numeric value functions are listed and described in the Built In Functions chapter string value expression string value expression string value expression string concatenation string factor string factor value expression primary string value function string concatenation gt string value expression concatenation operator string factor concatenation operator Specify a character string value a binary string value or a bit string value The BNF indicates that a string value expression can be formed by concatenation of two or more value expression primary The types of the value expression primary elements must be compatible that is all must be string or binary or bit string values character value function st
523. t method performs a COMMIT while the rollback method performs a ROLLBACK SQL statement The setSavepoint String name method performs a SAVEPOINT name SQL statement and returns a java sql Savepoint object The rollback Savepoint name method performs a ROLLBACK TO SAVEPOINT name SQL statement The Javadoc for JDBCConnection JDBCDriver JDBCDatabaseMetadata JDBCResultSet JDBCStatement JDBCPreparedStatement list all the supported JDBC methods together with information that is specific to HSQLDB Closing the Database All databases running in different modes can be closed with the SHUTDOWN command issued as an SQL statement When SHUTDOWN is issued all active transactions are rolled back The catalog files are then saved in a form that can be opened quickly the next time the catalog is opened A special form of closing the database is via the SHUTDOWN COMPACT command This command rewrites the data filethat contains the information stored in CACHED tables and compacts it to its minimum size This command should be issued periodically especially when lots of inserts updates or deletes have been performed on the cached tables Changes to the structure of the database such as dropping or modifying populated CACHED tables or indexes also create large amounts of unused file space that can be reclaimed using this command Databases are not closed when the last connection to the database is explicitly closed via JDBC A
524. t general Users generally refer to the SELECT statement when they mean a query specification or query expression Ifastatement begins with SELECT and has no UNION or other set operations then itis a query specification gt Otherwise itisa lt query expression Table In data access statements a table can be a database table or view or an ephemeral table formed for the duration of the query Some types of table are lt table primary gt and can participate in joins without the use of extra parentheses The BNF in the Table Primary section below lists different types of lt table primary gt Tables can also be formed by specifying the values that are contained in them lt table value constructor gt VALUES lt row value expression list gt lt row value expression list gt lt table row value expression gt lt comma gt lt table row value expression In the example below a table with two rows and 3 columns is constructed out of some values VALUES 12 14 null 10 11 CURRENT DATE When a table is used directly in a UNION or similar operation the keyword TABLE is used with the name e explicit table TABLE table or query name In the examples below all rows of the two tables are included in the union The keyword TABLE is used in the first example The two examples below are equivalent TABLE atable UNION TABLE anothertable SELECT FROM atable UNION SELEC
525. t block and remain active in any sub block and statement within the block The handlers become inactive when code execution leaves the block In the previous example if an exception is thrown during the execution of either SQL statement the execution of the compound statement is terminated and the exception is propagated and thrown by the CALL statement for the procedure A handler declaration can resolve the thrown exception within the compound statement without propagating it and allow the execution of the lt compound statement gt to continue In the example below the UNDO handler declaration catches any exception that is thrown during the execution of the compound statement inside the BEGIN END block As it is an UNDO handler all the changes to data performed within the compound statement BEGIN END block are rolled back The procedure then returns without throwing an exception CREATE PROCEDURE NEW_CUSTOMER IN firstname VARCHAR 50 IN lastname VARCHAR 50 IN address VARCHAR 100 MODIFIES SQL DATA label_one BEGIN ATOMIC DECLARE temp_id INTEGER DECLARE UNDO HANDLER FOR SQLEXCEPTION LEAVE label_one INSERT INTO CUSTOMERS VALUES DEFAULT firstname lastname CURRENT_TIMESTAMP SET temp_id IDENTITY INSERT INTO ADDRESSES VALUES DEFAULT temp_id address END Other types of hander are CONTINUE and EXIT handlers A CONTINUE handler ignores any exception and proceeds to the next statement in the block An EX
526. t is being updated or inserted or to prevent insert updated or deletes or to perform additional operations Some bad examples of SQL triggers in effect enforce an integrity constraint which would better be expressed as a CHECK constraint A trigger that causes an exception if the value inserted in a column is negative is such an example A check constraint that declares CHECK VALUE gt 0 declarative is a better way of expressing an integrity constraint than a trigger that throws an exception if the same condition is false Usage constraints cannot always be expressed by SQL s integrity constraint statements Triggers can enforce these constraints For example it is not possible to use a check constraint to prevent inserts or deletes on weekends A trigger can be used to enforce the time when each operation is allowed A trigger is declared to activate when an UPDATE INSERT or DELETE action is performed on a table These actions may be direct or indirect Indirect actions may arise from CASCADE actions of FOREIGN KEY constraints or from data change statements performed on a VIEW that is based on the table that in It is possible to declare multiple triggers on a single table The triggers activate one by one according to the order in which they were defined HyperSQL supports an extension to the CREATE TRIGGER statement which allows the user to specify the execution order of the new trigger A row level trigger allows access to
527. t just the generated columns but any set of columns of the table You can use this to retrieve the columns values that may be modified by a BEFORE TRIGGER on the table JDBC Callable Statement The JDBC CallableStatement interface is used to call Java or SQL procedures that have been defined in the database The SQL statement in the form of CALL procedureName with constant value arguments or with parameter markers Note that you must use a parameter marker for OUT and INOUT arguments of the procedure you are calling The OUT arguments should not be set before executing the callable statement After executing the statement you can retrieve the OUT and INOUT parameters with the appropriate getX XX method 98 HyperSGL Data Access and Change Procedures can also return one or more result sets You should call the getResultSet and getMoreResults methods to retrieve the result sets one by one SQL functions can also return a table You can call such functions the same way as procedures and retrieve the table as a ResultSet JDBC Returned Values The methods of the JDBC ResultSet interface can be used to return values and to convert value to different types as supported by the JDBC specification When a CLOB and BLOB object is returned from a ResultSet no data is transferred until the data is read by various methods of java sql CLOB and java sql BLOB Data is streamed in large blocks to avoid excessive memory use Arra
528. t paren datetime value expression minus sign datetime term right paren interval qualifier interval term interval factor interval term 2 asterisk factor interval term 2 solidus factor term asterisk interval factor interval factor sign interval primary interval primary value expression primary interval qualifier interval value function interval value expression 1 interval value expression interval term 1 interval term interval term 2 interval term Specify an interval value Details are described in the SQL Language chapter interval absolute value function interval value function interval value function interval absolute value function interval absolute value function ABS left paren interval value expression right paren Specify a function that returns the absolute value of an interval If the interval is negative it is negated otherwise the original value is returned boolean value expression boolean value expression boolean value expression boolean term boolean value expression OR boolean term boolean term boolean factor boolean term AND boolean factor boolean factor NOT boolean test boolean test boolean primary IS NOT truth value truth va
529. t paren gt lt referencing columns gt lt right paren gt lt references specification gt lt references specification gt REFERENCES lt referenced table and columns gt MATCH lt match type gt lt referential triggered action gt lt match type gt FULL PARTIAL SIMPLE lt referencing columns gt lt reference column list gt lt referenced table and columns gt lt table name gt lt left paren gt lt reference column list gt lt right paren gt lt reference column list gt lt column name list gt lt referential triggered action gt lt update rule gt lt delete rule gt lt delete rule gt lt update rule gt lt update rule gt ON UPDATE lt referential action gt lt delete rule gt ON DELETE lt referential action gt lt referential action gt CASCADE SET NULL SET DEFAULT RESTRICT NO ACTION A referential constraint allows links to be established between the rows of two tables The specified list of lt referencing columns gt corresponds one by one to the columns of the specified list of lt referenced columns gt in another table or sometimes in the same table For each row in the table a row must exist in the referenced table with equivalent values in the two column lists There must exist a single unique constraint in the referenced table on all the lt referenced columns gt 56 HyperSG
530. t select sublist lt select sublist gt derived column gt qualified asterisk gt lt qualified asterisk gt lt asterisked identifier chain gt lt period gt lt asterisk gt lt asterisked identifier chain lt asterisked identifier period lt asterisked identifier gt lt asterisked identifier gt lt identifier gt lt derived column gt lt value expression gt lt as clause gt lt as clause gt AS lt column name gt The qualifier DISTINCT or ALL apply to the results of the SELECT statement after all other operations have been performed ALL simply returns the rows while DISTINCT compares the rows and removes the duplicate ones Projection is performed by the lt select list gt A single lt asterisk gt means all columns of the lt table expression gt are included in the same order as they appear in the lt table expression An asterisk qualified by a table name means all the columns of the qualifier table name are included If an unqualified asterisk is used then no other items are allowed in the lt select list gt When the the lt table expression is the direct result of NATURAL or USING joins the use of lt asterisk gt includes the columns used for the join before the other columns A qualified asterisk does not cover the join columns A derived column is a value expression optionally named with the as clause A lt value express
531. t semicolon gt END lt ending label An example of a simple compound statement body is given below It performs the common task of inserting related data into two table The IDENTITY value that is automatically inserted in the first table is retrieved using the IDENTITYO function and inserted into the second table CREATE PROCEDURE new_customer firstname VARCHAR 50 lastname VARCHAR 50 address VARCHAR 100 MODIFIES SQL DATA BEGIN ATOMIC INSERT INTO customers VALUES DEFAULT firstname lastname CURRENT TIMESTAMP INSERT INTO addresses VALUES DEFAULT IDENTITY address END Table Variables A table variable declaration defines the name and columns of a local table that can be used in the routine body The table cannot have constraints Table variable declarations are made before scalar variable declarations BEGIN ATOMIC DECLARE TABLE temp table col a INT col b VARCHAR 20 DECLARE temp id INTEGER more statements END Variables A variable declaration defines the name and data type of the variable and optionally its default value In the next example a variable is used to hold the IDENTITY value In addition the formal parameters of the procedure are identified as input parameters with the use of the optional IN keyword This procedure does exactly the same job as the procedure in the previous example 145 HyperSQL SQL Invoked Routines CREATE PROCEDURE new
532. t to keep the data between the tests the best solution is to use a Server instance that has a mem database After the tests are done you can SHUTDOWN this database which will shutdown the server The Server has an option that allows databases to be created as needed by making a connection see the Listeners Chapter This option is useful for testing as your server is never shut down when a database is shutdown Each time you connect to the mem database that is served by the Server the database is created if it does not exist i e has been previously shut down If you do not want to run a Server instance and you need persistence between tests in different processes then you should use a file database From version 2 2 9 when the last existing connection to the database is closed the latest changes to the database are persisted fully The database is still in an open state until it is shut down You can use the shut down t rue connection property to close the database automatically after the connections are closed An alternative option is to use hsqldb write_delay false connection property but this is slightly slower than the other option and should be used in situations where the test application does not close the connections It has been reported that some data access frameworks do not close all their connection to the database after the tests In such situations you need to use zero WRITE DELAY if you want the data to persist at th
533. tabase URL Driver and Protocol Host and Port Example Database Example jdbc hsqldb res adirectory dbname 227 HyperSGL Properties Driver and Protocol Host and Port Example Database Example Database files can be loaded from one of the jars specified as part of the Java command the same way as resource files are accessed in Java programs The adirectory above stands for a directory in one of the jars Table 12 4 Server Database URL Driver and Protocol Host and Port Example Database Example jdbc hsqldb hsql localhost an alias jdbc hsqldb hsqls 192 0 0 10 9500 enrolments jdbc hsqldb http dbserver somedomain com quickdb jdbc hsqldb https The host and port specify the IP address or host name of the server and an optional port number The database to connect to is specified by an alias This alias is a lowercase string defined in the server properties file to refer to an actual database on the file system of the server or a transient in memory database on the server The following example lines in server properties or webserver properties define the database aliases listed above and accessible to clients to refer to different file and in memory databases The old form for the server URL e g jdbc hsqldb hsql localhost connects to the same database as the new form for the URL jdbc hsqldb hsq1 localhost where the alias is a zero length string Variables In Connection URL
534. table If FULL is specified the addition of leftover rows is performed from both the first and the second table These forms are expressed by prefixing the join specification with the given keyword For example A LEFT OUTER JOIN B ON search condition orA NATURAL FULL OUTER JOIN BorA FULL OUTER JOIN B USING comma separated column name list SELECT a b FROM a LEFT OUTER JOIN b ON a col one b col two Selection Despite the name selection has nothing to do with the list of columns in a SELECT statement In fact it refers to the search condition used to limit the rows that from a result table selection of rows not columns In SQL simple selection is expressed with a WHERE condition appended to a single table or a joined table In some cases this method of selection is the only method available For example in DELETE and UPDATE statements But when it is possible to perform the selection with join conditions this is the better method as it results in a clearer expression of the query Projection Projection is selection of the columns from a simple or joined table to form a result table Explicit projection is performed in the SELECT statement by specifying the select column list Some form of projection is also performed in JOIN USING and NATURAL JOIN 126 HyperSGL Data Access and Change The joined table has columns that are formed according to the rules mentioned above But in many c
535. table is combined with each row of the second table to fill the rows of the new table If the rows of each table form a set then the rows of the CROSS JOIN table form the Cartesian product of the rows of the two table operands Conditions are not allowed as part of a cross join which is simply A CROSS JOIN B Any conditions in a WHERE clause are later applied to the table resulting from the cross join Tables in the FROM CLAUSE separated with commas are equivalent to cross joins between the tables Two joined tables separated with a comma such as A B is equivalent to A CROSS JOIN B which means the joined tables A and B are populated separately before they are joined CROSS JOIN is not is not generally very useful as it returns large result tables unless WHERE conditions are used UNION JOIN The UNION JOIN has limited use in queries The result table has the same columns as that of CROSS JOIN Each row of the first table is extended to the right with nulls and added to the new table Each row of the second table is extended to the left with nulls and added to the new table The UNION JOIN is expressed as A UNION JOIN B This should not be confused with A UNION B which is a set operation Union join is for special applications and is not commonly used JOIN ON The condition join is similar to CROSS JOIN but a condition is tested for each row of the new table and the row is created only if the condition is true This form of join is
536. tatement computed for the current row The second argument is the boolean FALSE The third and fourth argument values can 161 HyperSQL SQL Invoked Routines have any type and are initially null but they can be updated in the body of the function during each invocation The third and fourth arguments act as registers and hold their values between invocations The return value of the function is ignored during the computation phase when the second parameter is FALSE After the computation phase the function is invoked once more to get the final result In this invocation the first argument is NULL and the second argument is boolean TRUE The third and fourth arguments hold the values they held at the end of the last invocation The value returned by the function in this invocation is used as the result of the aggregate function computation in the invoking SQL statement In SQL queries with GROUP BY the call sequence is repeated separately for each separate group SQL PSM Aggregate Functions The example below features a user defined version of the Standard AVG value expression aggregate function for INTEGER input and output types This function behaves differently from the Standard AVG function as it returns O when all the input values are null CREATE AGGREGATE FUNCTION udavg IN x INTEGER IN flag BOOLEAN INOUT addup BIGINT INOUT counter INT RETURNS INTEGER CONTAINS SQL BEGIN ATOMIC IF flag THEN RETURN addup count
537. tement HyperSQL set password statement SET PASSWORD password Set the password for the current user password is a string enclosed with single quote characters and is case sensitive SET INITIAL SCHEMA set the initial schema for the current user HyperSQL set initial schema statement SET INITIAL SCHEMA schema name DEFAULT Change the initial schema for the current user The initial schema is the schema used by default for SOL statements issued during a session If DEFAULT is used the default initial schema for all users is used as the initial schema for the current user The separate SET SCHEMA command allows the user to change the schema for the duration of the session See also the Sessions and Transactions chapter SET DATABASE DEFAULT INITIAL SCHEMA set the default initial schema for all users HyperSQL set database default initial schema statement SET DATABASE SCHEMA schema name zj is EFAULT INITIAL Sets the initial schema for new users This schema can later be changed with the lt set initial schema statement gt command 91 HyperSGL Access Control CREATE ROLE role definition role definition CREATE ROLE role name WITH ADMIN lt grantor gt Defines a new role Initially the role has no rights except those of the PUBLIC role Only a user with the DBA role can execute this command DROP ROLE drop
538. tements For each row where the object is referenced its value is incremented There is a separate name space for SEQUENCE objects IDENTITY columns are columns of tables which have an internal unnamed SEQUENCE object HyperSQL also supports IDENTITY columns that use a named SEQUENCE object SEQUENCE objects and IDENTITY columns are supported fully according to the latest SQL 2008 Standard syntax Sequences 44 HyperSGL Schemas and Database Objects The SQL 2008 syntax and usage is different from what is supported by many existing database engines Sequences are created with the CREATE SEQUENCE command and their current value can be modified at any time with ALTER SEQUENCE The next value for a sequence is retrieved with the NEXT VALUE FOR name expression This expression can be used for inserting and updating table rows Example 4 1 inserting the next sequence value into a table row INSERT INTO mytable VALUES 2 John NEXT VALUE FOR mysequence You can also use it in select statements For example if you want to number the returned rows of a SELECT in sequential order you can use Example 4 2 numbering returned rows of a SELECT in sequential order SELECT NEXT VALUE FOR mysequence coll col2 FROM mytable WHERE In version 2 0 the semantics of sequences is exactly as defined by SQL 2008 If you use the same sequence twice in the same row in an INS
539. tension and not part of the SQL Standard CAST An array can be cast into an array of a different type Each element of the array is cast into the element type of the target array type UNNEST Arrays can be converted into table references with the UNNEST keyword UNNEST array value expression WITH ORDINALITY The lt array value expression gt can be any expression that evaluates to an array A table is returned that contains one column when WITH ORDINALITY is not used or two columns when WITH ORDINALITY is used The first column contains the elements of the array including all the nulls When the table has two columns the second column contains the ordinal position of the element in the array When UNNEST is used in the FROM clause 25 HyperSGL SQL Language of a query it implies the LATERAL keyword which means the array that is converted to table can belong to any table that precedes the UNNEST in the FROM clause This is explained in the Data Access and Change chapter COMPARISON Arrays can be compared for equality but they cannot be compared for ordering or ranges Array expressions are therefore not allowed in an ORDER BY clause or in a comparison expression such as GREATER THAN Two arrays are equal if they have the same length and the values at each index position are either equal or both NULL USER DEFINED FUNCTIONS and PROCEDURES Array parameters variables and return values can be specified in u
540. th gt Examples below Connection c DriverManager getConnection jdbc hsqldb hsql localhost xdb file C files mycdatalbasecu SAW TRY Connection c DriverManager getConnection jdbc hsqldb hsql localhost xdb mem test sql enforce_types true SA Connection c DriverManager getConnection jdbc hsqldb hsql localhost xdb filepath file C files mydatabase SA The path can be a file or mem database Specifying Database Properties at Server Start Each database started by a Server has its own URL When new databases are created by the server the database properties for each of the new database can be appended to the database URL Examples below example in server propertie file server database 0 file opt db accounts hsqldb default table type cached sql enforce names true server dbname 0 accounts example for setting the property programatically HsqlProperties p new HsqlProperties 246 HyperSGL HyperSQL Network Listeners Servers p setProperty server database 0 file opt db accounts hsqldb default table type cached sql enforce names true The specified properties apply only to a new database They have no effect on an existing database apart from a few properties such as readonly listed in the Properties chapter TLS Encryption Listener TLS Support a k a SSL Blaine Simpson The HSQL Development Group SRevision 4903 2012 08 06 00 12
541. that opens the database It has no effect if used with subsequent connections This command has two uses One is for test suites where connections to the database are made from one JVM context immediately followed by another context The other use is for applications where it is not easy to configure the environment to shutdown the database Examples reported by users include web application servers where the closing of the last connection coincides with the web app being shut down jdbc hsqldb file enrolments shutdown true In addition when the first connection to an in process file or mem database creates a new database all the user defined database properties can be specified as URL properties See the next section for details Database Properties in Connection URL and Properties The database engine has several properties that are listed in the System Management chapter These properties can be changed via SQL commands after a connection is made to the database It is possible to specify most of these properties in the connection properties or as part of the URL string when the first connection is made to a new file or mem database This allows the properties to be set without using any SQL commands The corresponding SQL command is given for each property If the properties are used for connection to an existing database they are ignored The exceptions are the following property settings that are allowed for the
542. that the server provides access to 3 different databases Two of the databases are file based while the third is all in memory The aliases for the databases that the users connect to are accounts enrolments and quickdb All the above properties and their values can be specified on the command line to start the server by omitting the server prefix If a property value pair is specified on the command line it overrides the property value specified inthe server properties or webserver properties file Note Upgrading If you have existing custom properties files change the values to the new naming convention Note the use of digits at the end of server database n and server dbname n properties 245 HyperSGL HyperSQL Network Listeners Servers Starting a Server from your Application If you want to start the server from within your application as opposed to the command line or batch files you should create an instance of Server or Web Server then assign the properties and start the Server An working example of this can be found in the org hsqldb test TestBase source The example below sets the same properties as in the server properties file example HsqlProperties p new HsqlProperties p setProperty server database 0 file opt db accounts p setProperty server dbname 0 an alias set up the rest of properties alternative to the above is Server server new Server server setP
543. the CHECKPOINT statement 3 Perform all the bulk operations using batched prepared statements A batch size of 1000 to 10000 is adequate 4 After all the bulk operations are complete execute the SET FILES LOG TRUE statement 5 Finally execute the CHECKPOINT statement 6 If you have performed many thousands of updates or deletes not just inserts it is a good idea to execute CHECKPOINT DEFRAG instead of CHECKPOINT at the end 7 If things go wrong during the bulk operation for example when a unique constraint violation aborts the operation and you want to redo the operation just use SHUTDOWN IMMEDIATELY instead of CHECKPOINT When you restart the database it will revert to the state at the first CHECKPOINT and the bulk operation can be redone Using NIO File Access This method of file access uses the operating system s memory mapped file buffer for the data file For larger databases with CACHED tables use of nio improves database access speed significantly Performance improvements can be tenfold or even higher By default NIO is used for data files from 16 MB up to 256 MB You can increase the limit with the SET FILES NIO SIZE lt value gt statement There should be enough RAM available to accommodate the memory mapped buffers For vary large nio usage a 64 bit JVM must be used The memory is not taken from the JVM memory allocation therefore there is no need to increase the Xmx parameter of the JVM If not enough memory is avai
544. the INTERVAL type of the expressions The YEAR MONTH options may be valid for INTERVAL types based on months The DAY HOUR MINUTE SECOND SECONDS MIDNIGHT options may be valid for INTERVAL types based on seconds For example DAY HOUR MINUTE are the only valid fields for the INTERVAL DAY TO MINUTE data type Foundation with HyperSQL extensions Functions for Datetime Arithmetic TIMESTAMPADD TIMESTAMPADD tsi datetime field numeric value expression datetime value expr gt TIMESTAMPDIFF TIMESTAMPDIFF lt tsi datetime field gt lt datetime valu xpr 1 gt lt datetime value expr 2 gt lt tsi datetime field gt SQL_TSI_FRAC_SECOND SQL_TSI_SECOND SQL_TSI_MINUTE SOL TSI HOUR SOL TSI DAY SOL TSI WEEK SOL TSI MONTH SOL TSI QUARTER SOL TSI YEAR I HyperSQL supports full SQL Standard datetime features It supports adding integers representing units of time directly to datetime values using the arithmetic plus operator It also supports subtracting one datetime valu xpr from another in the given units of date or time using the minus operator An example of datetime valu xpr numeric value expression datetime field is LOCALTIMESTAMP 5 DAY Anexample of datetime valu xpr gt lt numeric value expression gt lt datetime field gt is CURRENT DATE DATE 2008 08 8 MONTH which returns the number of calendar months between
545. the file via memory mapped buffers Only a user with the DBA role can execute this statement This is equivalent to the connection property hsqldb nio data file SET FILES NIO SIZE set files nio size set files nio size statement SET FILES NIO SIZE unsigned integer literal Sets The maximum size of data file in megabytes that can use the nio access method When the file gets larger than this limit non nio access methods are used Values 64 128 256 512 1024 and larger multiples of 512 can be used The default is 256MB Only a user with the DBA role can execute this statement This is equivalent to the connection property hsgldb nio max size SET FILES WRITE DELAY set files write delay statement set files write delay statement SET FILES WRITE DELAY TRUE FALSE seconds value milliseconds value MILLIS Set the WRITE DELAY property of the database The WRITE DELAY controls the frequency of file sync for the log file When WRITE DELAY is set to FALSE or 0 the sync takes place immediately at each COMMIT WRITE DELAY TRUE performs the sync once every 0 5 seconds which is the default A numeric value can be specified instead The purpose of this command is to control the amount of data loss in case of a total system crash A delay of 1 second means at most the data written to disk during the last second before the crash is lost All data written prior to t
546. the length are 16 HyperSGL SQL Language spaces Shorter strings are padded with the space character when inserted into a CHARACTER column Similar rules are applied to VARBINARY and BINARY columns For BINARY columns the padding and truncation rules are applied with zero bytes instead of spaces Explicit CAST of a value to a CHARACTER or VARCHAR type will result in forced truncation or padding So a test suchas CAST mycol AS VARCHAR 2 xy will find the values beginning with xy This is the equivalent of SUBSTRING mycol FROM 1 FOR 2 xy For all numeric types the rules of explicit cast and implicit conversion are the same If cast or conversion causes any digits to be lost from the fractional part it can take place If the non fractional part of the value cannot be represented in the new type cast or conversion cannot take place and will result in a data exception There are special rules for DATE TIME TIMESTAMP and INTERVAL casts and conversions Datetime types HSQLDB fully supports datetime and interval types and operations including all relevant optional features as specified by the SQL Standard since SQL 92 The two groups of types are complementary The DATE type represents a calendar date with YEAR MONTH and DAY fields The TIME type represents time of day with HOUR MINUTE and SECOND fields plus an optional SECOND FRACTION field The TIMESTAMP type represents the combination of DATE and TIME types
547. the server For multiple args put quotes around entire value SERVER JVMARGS Xmx512m You can set the javax net debug property on the server side here in the same exact way as shown for the client side above Verify that the init script works Just run path to hsqldb as root to see the arguments you may use Notice that you can run 263 HyperSGL HyperSQL on UNIX path to hsqldb status at any time to see whether your HSQLDB Listener is running Re run the script with each of the possible arguments to really test it good If anything doesn t work right then see the Troubleshooting the Init Script section 5 Tell your OS to run the init script upon system startup and shutdown If you are using a UNIX variant that has etc rc conf or etc rc conf local like BSD variants and Gentoo you must set hsqldb enable to YES in either of those files Justrun cd etc ls rc conf rc conf local to see if you have one of these files For good UNIXes that use System V style init you must set up hard links or soft links either manually or with management tools such as chkconfig or insserv or Gui s like run level editors This paragraph is for Mac OS X users only If you followed the instructions above your init script should reside at Library StartupItems hsqldb hsqldb Now copy the file StartupParameters plist from the directory src org hsqldb sample of your HSQLDB distribution to the
548. the table mytable to a vertical bar place the following in the SET TABLE SOURCE statement for example SET TABLE mytable SOURCE myfile fs Since HSQLDB treats CHAR and VARCHAR strings the same the ability to assign a different separator to the latter is provided When a different separator is assigned to a VARCHAR it will terminate any CSV field of that type For example if the first field is CHAR and the second field VARCHAR and the separator fs has been defined as the pipe l and vs as the period then the data in the CSV file for a row will look like First field data Second field data Third field data This facility in effect offers an extra special separator which can be used in addition to the global separator The following example shows how to change the default separator to the pipe l VARCHAR separator to the period within a SET TABLE SOURCE statement SET TABLE mytable SOURCE myfile fs vs HSQLDB also recognises the following special indicators for separators special indicators for separators semi semicolon quote single quote space space character apos apostrophe n newline Used as an end anchor like in regular expressions r carriage return t tab M backslash AA a Unicode character specified in hexadecimal 83 HyperSGL Text Tables Furthermore HSQLDB provides csv file support with three additional boolean options ignore first quoted and
549. the time of the next startup all such files will be deleted by the database engine In some circumstances a test data xxx old is created and deleted afterwards by the database engine The user can delete these test data xxx old files A res catalog consists of the files for a small read only database that can be stored inside a Java resource such as a ZIP or JAR archive and distributed as part of a Java application program HyperSGL Running and Using HyperSQL In Process Access to Database Catalogs In general JDBC is used for all access to databases This is done by making a connection to the database then using various methods of the java sq1 Connection object that is returned to access the data Access to an in process database is started from JDBC with the database path specified in the connection URL For example if the file database name is testdb and its files are located in the same directory as where the command to run your application was issued the following code is used for the connection Connection c DriverManager getConnection jdbc hsqldb file testdb SA The database file path format can be specified using forward slashes in Windows hosts as well as Linux hosts So relative paths or paths that refer to the same directory on the same drive can be identical For example if your database directory in Linux is opt db containing a database testdb with files named testdb then the d
550. the two dates The two JDBC functions TIMESTAMPADD and TIMESTAMPDIFF perform the same function as above SQL expressions The field names are keywords and are different from those used in the EXTRACT functions These names 186 HyperSQL Built In Functions are valid for use only when calling these two functions The return value for TIMESTAMPADD is of the same type as the datetime argument used The return type for TIMESTAMPDIFF is always BIGINT regardless of the type of arguments The two datetime arguments of TIMESTAMPDIFF should be of the same type TIMESTAMPDIFF is evaluated as datetime value expr 2 lt datetime value expr 1 JDBC TIMESTAMPADD SQL TSI MONTH 3 DATE 2008 11 22 TIMESTAMPDIFF SOL TSI HOUR TIMESTAMP 2008 11 20 20 30 40 TIMESTAMP 2008 11 21 21 30 40 DATE ADD DATE ADD datetime valu xpr gt interval value expr gt DATE SUB DATE SUB datetime valu xpr gt interval value expr gt These functions are equivalent to arithmetic addition and subtraction datetime value expr interval value expr and datetime value expr interval value expr The functions are provided for compatibility with other databases The supported interval units are the standard SQL interval unit listed in other chapters of this guide HyperSQL DATE ADD DATE 2008 11 22 INTERVAL 3 MONTH DATE SUB TIMESTAMP 2008 11
551. the type codes for WITH TIME ZONE types will be SQL type codes as opposed to JDBC type codes 216 HyperSQL System Management Only a user with the DBA role can execute this statement This is equivalent to the connection property jdbc translate_tti_types SET DATABASE SQL CONCAT NULLS set database sql concat nulls statement lt set database sql concat nulls statement gt TRUE FALSE SET DATABASE SQL CONCAT NULLS When the property is TRUE concatenation of a null value with a not null value results in a null value When the property is FALSE this type of concatenation result in the not null value Setting this property FALSE results in concatenation behaviour similar to Oracle or MS SQL Server SQL Standard requires a NULL result The property is TRUE by default Only a user with the DBA role can execute this statement This is equivalent to the connection property sql concat_nulls SET DATABASE SQL UNIQUE NULLS set database sql unique nulls statement set database sql unique nulls statement TRUE FALSE I SET DATABASE SOL UNIQUE NULLS When the property is TRUE with multi column UNIQUE constraints it is possible to insert multiple rows for which one or more of the values for the constraint columns is NULL When the property is FALSI E if there is any not null value in the columns then the set of values is compared to the existing rows
552. therwise it is turned to uppercase password isa string enclosed with single quote characters and is case sensitive 90 HyperSGL Access Control Only a user with the DBA role can execute this command ALTER USER SET INITIAL SCHEMA set the initial schema for a user HyperSQL alter user set initial schema statement ALTER USER user name SET INITIAL SCHEMA schema name DEFAULT Change the initial schema for a user The initial schema is the schema used by default for SQL statements issued during a session If DEFAULT is used the default initial schema for all users is used as the initial schema for the user The SET SCHEMA command allows the user to change the schema for the duration of the session Only a user with the DBA role can execute this statement ALTER USER SET LOCAL set the user authentication as local HyperSQL alter user set local ALTER USER user name SET LOCAL TRUE FALSE Sets the authentication method for the user as local This statement has an effect only when external authentication with role names is enabled In this method of authentication users created in the database are ignored and an external authentication mechanism such as LDAP is used This statement is used if you want to use local password authentication for a specific user Only a user with the DBA role can execute this statement SET PASSWORD set password sta
553. thout firing its triggers This statement can only be used on base tables not views If the table is referenced in a FOREIGN KEY constraint defined on another table the statement causes an exception Triggers defined on the table are not executed with this statement The default for identity column restart option is CONTINUE IDENTITY This means no change to the IDENTITY sequence of the table If RESTART IDENTITY is specified then the sequence is reset to its start value I TRUNCATE is faster than ordinary DELETE The TRUNCATE statement is an SQL Standard data change statement therefore it is performed under transaction control and can be rolled back if the connection is not in the auto commit mode HyperSQL also supports the optional AND COMMIT and NO CHECK options If AND COMMIT is used then the transaction is committed with the execution of the TRUNCATE statement The action cannot be rolled back If the additional NO CHECK option is also specified then the TRUNCATE statement is executed even if the table is referenced in a FOREIGN KEY constraint defined on another non empty table This form of TRUNCATE is faster than the default form and does not use much memory TRUNCATE SCHEMA truncate schema statement T lt truncate schema statement gt TRUNCATE SCHEMA lt target schema gt lt identity column restart option AND COMMIT NO CHECK Performs the equivalent of aTRUNCATE TABLE AND COMMIT o
554. tion SUBSTRING returns a character string that consists of length characters from char value expr gt starting at the offset position JDBC SUBSTRING SUBSTRING char value expr gt FROM start position FOR string length USING CHARACTERS SUBSTRING binary value expr gt FROM start position FOR string length The character version of SUBSTRING returns a character string that consists of the characters of the char value expr from start position Iftheoptional string length is specified only string length characters are returned The binary version of SUBSTRING returns a binary string in the same manner Foundation TRIM TRIM LEADING TRAILING BOTH trim character FROM char value expr gt TRIM LEADING TRAILING BOTH trim octet gt FROM binary value expr gt The character version of TRIM returns a character string based on char value expr Consecutive instances of trim character are removed from the beginning the end or both ends of the lt char value expr gt depending on the value of the optional first qualifier LEADING TRAILING BOTH J If no qualifier is specified BOTH is used as default If trim character is not specified the space character is used as default The binary version of TRIM returns a binary string based on binary value expr Consecutive instances of trim octet are removed in t
555. tion with OS specific daemon administration guis etc you do have a well tested and well behaved script that gives good utilitarian feedback Init script Setup Procedure The strategy taken here is to get the init script to run your single Server or WebServer first as specified by TARGET CLASS After that s working you can customize the JVM that is run by running additional Listener instances in it running your own application in it embedding or even overriding HSQLDB behavior with your own overriding classes 1 Copy the init script sample hsqldb init to hsqldb in the directory where init scripts live on your variety of UNIX The most common locations are etc init dor etc rc d init don System V style UNIXes usr local etc rc don BSD style UNIXes and Library StartupItems hsqldb on OS X you ll need to create the directory for the last 2 View your server properties file Make a note of every catalog define by a server database X setting A couple steps down you will need to set up administrative access for each of these catalogs If you are using our sample server properties file you will just need to set up access for the catalog specified with ile db0 dbo Note Pre 2 0 versions of the hsqldb init script required use of properties settings of the formserver urlid X These settings are obsolete and should be removed 3 Either copy HSQLDB OWNER s sqltool rc file into root s home directory or set the value of
556. tname lastname VALUES DEFAULT Felix the Cat INSERT INTO movies starid movieid title VALUES CURRENT VALUE FOR seq 10 Felix in Hollywood Tables In the SQL environment tables are the most essential components as they hold all persistent data If TABLE is considered as metadata i e without its actual data it is called a relation in relational theory It has one or more columns with each column having a distinct name and a data type A table usually has one or more constraints which limit the values that can potentially be stored in the TABLE These constraints are discussed in the next section 46 HyperSGL Schemas and Database Objects A single column of the table can be defined as IDENTITY The values stored in this column are auto generated and are based on an unnamed identity sequence or optionally a named SEQUENCE object Views A VIEW is similar to a TABLE but it does not permanently contain rows of data A view is defined as a QUERY EXPRESSION which is often a SELECT statement that references views and tables but it can also consist of a TABLE CONSTRUCTOR that does not reference any tables or views A view has many uses Hide the structure and column names of tables The view can represent one or more tables or views as a separate table This can include aggregate data such as sums and averages from other tables Allow access to specific rows in a table For example allow access
557. to records that were added since a given date while hiding older records Allow access to specific columns For example allow access to columns that contain non confidential information Note that this can also be achieved with the GRANT SELECT statement using column level privileges A VIEW that returns the columns of a single ordinary TABLE is updatable if the query expression of the view is an updatable query expression as discussed in the Data Access and Change chapter Some updatable views are insertable into because the query expression is insertable into In these views each column of the query expressions must be a column of the underlying table and those columns of the underlying table that are not in the view must have a default clause or be an IDENTITY or GENERATED column When rows of an updatable view are updated or new rows are inserted or rows are deleted these changes are reflected in the base table A VIEW definition may specify that the inserted or updated rows conform to the search condition of the view This is done with the CHECK OPTION clause A view that is not updatable according to the above paragraph can be made updatable or insertable into by adding INSTEAD OF triggers to the view These triggers contain statements to use the submitted data to modify the contents of the underlying tables of the view separately For example a view that represents a SELECT statements that joins two tables can have an INSTEAD OF DELETE tri
558. to the break statement is C and Java But it can be used in compound statements as well leave statement LEAVE statement label Raising Exceptions Signal and Resignal Statements allow the routine to throw an exception If used with the IF or CASE conditions the exception is thrown conditionally SIGNAL signal statement The SIGNAL statement is used to throw an exception or force an exception When invoked any exception handler for the given exception is in turn invoked If there is no handler the exception is propagated to the enclosing context In its simplest form when there is no exception handler for the given exception routine execution is halted any change of data is rolled back and the routine throws the exception By default the message for the exception is taken from the predefined exception message for the specified SOLSTATE A custom message can be specified with the optional SET clause signal statement SIGNAL SOLSTATE state value SET MESSAGE TEXT character string literal RESIGNAL resignal statement The RESIGNAL statement is used to throw an exception from an exception handlers SOL procedure statement in effect propagating the exception to the enclosing context without further action by the currently active handlers By default the message for the exception is taken from the predefined exception message for the specified SOLSTATE A custom message can be s
559. tory path of database files it therefore cannot contain the double dot notation for parent directory This path is then appended by the engine to the directory path to form a full path When the property is true the path is not appended to the directory path and is used as it is to open the file In this usage the path can be relative or absolute All in memory databases can use text tables In this usage the path must be an absolute path These text tables are always read only To disable this capability for access control reasons the textdb allow full path property can be set false as a Java system property Blank lines are allowed anywhere in the text file and are ignored It is possible to define a primary key identity column unique foreign key and check constraints for text tables When a table source file is used with the ignore first true option the first ignored line is replaced with a blank line after a SHUTDOWN COMPACT unless the SOURCE HEADER statement has been used An existing table source file may include CHARACTER fields that do not begin with the quote character but contain instances of the quote character These fields are read as literal strings Alternatively if any field begins with the quote character then it is interpreted as a quoted string that should end with the quote character and any instances of the quote character within the string is doubled When any field containing the quote character or the separator is wr
560. ts on the schema objects to a grantee CREATE_SCHEMA the CREATE_SCHEMA role HyperSQL specific An authorization that has this role can create schemas The DBA authorization has this role and can grant it to other authorizations CHANGE_AUTHORIZATION the CHANGE AUTHORIZATION role HyperSQL specific A user that has this role can change the authorization for the current session to another user The other user cannot have the DBA role otherwise the original user would gain DBA privileges The DBA authorization has this role and can grant it to other authorizations 88 HyperSGL Access Control SYS User the SYS user HyperSQL specific This user is automatically created with a new database and has the DBA role This user name and its password are defined in the connection properties when connecting to the new database to create the database As this user it is possible to change the password create other users and created new schema objects The initial SYS user can be dropped by another user that has the DBA role As a result there is always at least one SYS user in the database Listing Users and Roles Tables in the INFORMATION SCHEMA contain the list of users and roles for the database The SYSTEM USERS tables contains the list of users with some extra settings for each user The AUTHORIZATIONS table contains a list of both users and roles Several other INFORMATION SCHEMA tables list the privileges granted to users a
561. ualified routine name SQL parameter declaration list returns clause routine characteristics routine body Parameter declaration list has been described above For SQL JRT routines the SQL parameter name is optional while for SQL PSM routines it is required If the parameter mode of a parameter is OUT or INOUT it must be specified The BNF is given below SQL parameter declaration list left paren SQL parameter declaration comma SQL parameter declaration right paren SQL parameter declaration parameter mode SQL parameter name lt parameter type lt parameter mode IN OUT INOUT lt parameter type data type Return Value and Table Functions RETURNS returns clause The returns clause specifies the type of the return value of a function not a procedure For all SOL PSM functions and ordinary SQL JRT functions this is simply a type definition which can be a built in type a DOMAIN type or a DISTINCT type or alternatively a TABLE definition For example RETURNS INTEGER For a SQL JRT function it is possible to define a returns table type for a Java method that returns a java sql ResultSet object Such SQL JRT functions are called table functions Table functions are used differently from normal functions A table function can be used in an SQL query expression exactly where a normal table or view is allowed
562. ue specification 135 HyperSGL Data Access and Change Update rows or insert new rows into the target table The MERGE statement uses a second table specified by table reference to determine the rows to be updated or inserted It is possible to use the statement only to update rows or to insert rows but usually both update and insert are specified The search condition matches each row of the table reference with each row of the target table Ifthe two rows match then the UPDATE clause is used to update the matching row of the target table Those rows of table reference that have no matching rows are then used to insert new rows into the target table Therefore a MERGE statement can update between 0 and all the rows of the target table andcan insert between 0 and the number of the rows in table reference into the target table If any row inthe target table matches more than one row in table reference acardinality error is raised On the other hand several rows inthe target table can match a single row in table reference without any error The constraints and referential actions specified on the database tables are enforced the same way as for an update and an insert statement The MERGE statement can be used with only the WHEN NOT MATCHED clause as a conditional INSERT statement that inserts a row if no existing rows match a condition In the first example below the table orig
563. uery The use of lateral derived table completely transforms the way a query is written For example the two queries below are equivalent but with different forms The query with LATERAL is evaluated separately for each row of the first table that satisfies the WHERE condition The example below uses the tables that are created and populated in DatabaseManagerSwing with the Insert test data menu option The first query uses a scalar subquery to compute the sum of invoice values for each customer The second query is equivalent and uses a join with a LATERAL table SELECT firstname lastname SELECT SUM total FROM invoice WHERE customerid customer id s FROM customer SELECT firstname lastname a c FROM customer LATERAL SELECT SUM total FROM invoice WHERE customerid customer id a c UNNEST UNNEST is similar to LATERAL but instead of a query expression one or more expressions that return an array are used These expressions are converted into a table which has one column for each expression and contains the elements of the array If WITH ORDINALITY is used an extra column that contains the index of each element is added to this table The number or rows in the table equals the length of the largest arrays The smaller arrays are padded with NULL values If an lt array value expression gt evaluates to NULL an empty array is used in its place The array expression can contain references to any column of the table refe
564. uide guide html PDF guide pdf http hsqldb org doc 2 0 guide guide pdf If you are reading this document now with a standalone PDF reader the your distro links may not work xiii HyperSQL Chapter 1 Running and Using HyperSQL Fred Toussi The HSQL Development Group Revision 5039 Copyright 2002 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 The HSQLDB Jar The HSQLDB jar package is located in the lib directory of the ZIP package and contains several components and programs Components of the Hsqldb jar package HyperSQL RDBMS Engine HSQLDB HyperSQL JDBC Driver Database Manager GUI database access tool with Swing and AWT versions Sql Tool command line database access tool The HyperSQL RDBMS and JDBC Driver provide the core functionality An additional jar contains Sql Tool command line database access tool SqITool and the DatabaseManagers are general purpose database tools that can be used with any database engine that has a JDBC driver Running Database Access Tools The tools are used for interactive user access to databases including creation of a database inserting or modifying data or querying the database All to
565. upgrading their HyperSQL installation Most users will not have customized the init script itself and your customizations will all be encapsulated in the init script configuration file These users should just overwrite their init script with a new one from the HyperSQL installation and manually merge config file settings First just copy the file sample hsqldb init over top of of your init script wherever it runs from Then update your old config file according to the instructions in the new config file template at sample hsqldb cfg You will have to change very few settings If you are upgrading from a pre 2 0 installation to a post 2 0 installation you will need to 1 add the setting URLIDS as described above and in the inline comments and 2 replace variable HSQLDB JAR PATH with SOLTOOL JAR PATH which if you haven t guessed should be set to the path to your sqltool jar file Users who customized their init script will need to merge their customizations into the new init script 265 HyperSQL Chapter 15 Deployment Guide Fred Toussi The HSQL Development Group Revision 5035 Copyright 2002 2012 Fred Toussi Permission is granted to distribute this document without any alteration under the terms of the HSQLDB license Additional permission is granted to the HSQL Development Group to distribute this document with or without alterations under the terms of the HSQLDB license 2012 08 06 00 12 50 0100 Memory and Di
566. urrent transaction The property should not be changed unless the application can quickly perform an alternative statement to continue or roll back the transaction This allows maximum flexibility and compatibility with other database engines which do not roll back the transaction upon deadlock When transactions are running in REPEATABLE READ or SERIALIZABLE isolation levels conflict is more likely to happen There is no difference in operation between these two isolation levels This isolation level is called SNAPSHOT ISOLATION In this mode when the duration of two transactions overlaps if one of the transactions has modified a row and the second transaction wants to modify the same row the action of the second transaction will fail The engine will invalidate the second transaction and roll back all its changes If the setting is changed to false with the set database transaction rollback on conflict statement then the second transaction will just return an error without rolling back The application must perform an alternative statement to continue or roll back the transaction In the MVCC model READ UNCOMMITTED is promoted to READ COMMITTED as the new architecture is based on multi version rows for uncommitted data and more than one version may exist for some rows With MVCC when a transaction only reads data then it will go ahead and complete regardless of what other transactions may do This does not depend on the transaction being
567. used to create the UNION table SELECT FROM atable UNION CORRESPONDING BY u v SELECT FROM anothertable The type of each column of the query expression is determined by combining the types of the corresponding columns from the two participating tables Ordering When the rows of the result table have been formed it is possible to specify the order in which they are returned to the user The ORDER BY clause is used to specify the columns used for ordering and whether ascending or descending ordering is used It can also specify whether NULL values are returned first or last SELECT x y AS xysum y z AS yzsum FROM atable AS t u v w x y Z WHERE u v w ORDER BY xysum NULLS LAST yzsum NULLS FIRST The ORDER BY clause specifies one or more value expressions The list of rows is sorted according to the first value expression When some rows are sorted equal then they are sorted according to the next value expression and so on lt order by clause ORDER BY sort specification comma sort Specification sort specification gt lt value expression collate clause ASC DESC NULLS FIRST NULLS LAST The defaults are ASC and NULLS FIRST 130 HyperSGL Data Access and Change A collation is used for columns of an ORDER BY expression that are of the type CHAR or VARCHAR Ifa collate clause is not specified then the collation of the
568. uthentication 205 EXTERNAL NAME 140 EXTRACT function 185 F FLOOR function 179 FOREIGN KEY constraint 56 FOR loop in routines 150 G generated column specification 54 303 HyperSQL General Index GET DIAGNOSTICS 136 Gradle 282 GRANTED BY 92 GRANT privilege 92 GRANT role 93 GREATEST function 192 GROUPING OPERATIONS 128 H HEXTORAW function 174 HOUR function 184 identifier chain 103 identifier definition 49 IDENTITY function 194 IF EXISTS 50 IFNULL function 192 IF STATEMENT 151 INFORMATION SCHEMA CATALOG NAME 76 init script 259 IN predicate 112 INSERT function 174 INSERTINTO 133 interval absolute value function 110 interval term 110 INTERVAL types 20 IS AUTOCOMMIT function 195 IS READONLY DATABASE FILES function 195 IS READONLY DATABASE function 195 IS READONLY SESSION function 195 IS DISTINCT predicate 115 ISNULL function 192 IS NULL predicate 113 ISOLATION LEVEL function 195 J JOIN USING 125 JOIN with condition 125 K KEY COLUMN USAGE 77 L LANGUAGE 141 LATERAL 123 LCASE function 174 LEAST function 193 LEFT function 174 LENGTH function 174 LIKE predicate 113 LN function 180 LOAD FILE function 193 LOB ID function 196 LOCALTIME function 183 LOCALTIMESTAMP function 183 LOCATE function 174 LOCK TABLE 37 LOG1O function 180 LOG function 180 LOOP in routines 149 LPAD function 174 LTRIM functi
569. valent The type TINYINT is an HSQLDB extension to the SQL Standard while the others conform to the Standard definition The SQL type dictates the maximum and minimum values that can be held in a field of each type For example the value range for TINYINT is 128 to 127 The bit precision of TINYINT SMALLINT INTEGER and BIGINT is respectively 8 16 32 and 64 For NUMERIC and DECIMAL decimal precision is used DECIMAL and NUMERIC with decimal fractions are mapped to java math BigDecimal and can have very large numbers of digits In HyperSQL the two types are equivalent These types together with integral types are called exact numeric types 11 HyperSGL SQL Language In HyperSQL REAL FLOAT DOUBLE are equivalent and all mapped to double in Java These types are defined by the SQL Standard as approximate numeric types The bit precision of all these types is 64 bits The decimal precision and scale of NUMERIC and DECIMAL types can be optionally defined For example DECIMAL 10 2 means maximum total number of digits is 10 and there are always 2 digits after the decimal point while DECIMAL 10 means 10 digits without a decimal point The bit precision of FLOAT can also be defined but in this case it is ignored and the default bit precision of 64 is used The default precision of NUMERIC and DECIMAL when not defined is 100 Note If a database has been setto ignore type precision limits with the SET DATABASE SQL SIZE FALSE comm
570. ve the JDBC ResultSet In the routine definition the DYNAMIC RESULT SETS clause must be used to specify a value above zero The DECLARE CURSOR statement is used after any variable declaration in compound statement block The SELECT statement should be followed with FOR READ ONLY to avoid possible error messages The lt open statement gt is then executed for the cursor at the point where the result set should be populated After the procedure is executed with a JDBC CallableStatement execute method all the result sets that were opened are returned to the JDBC CallableStatement Calling getResultSet will return the first ResultSet When there are multiple result sets the getMoreResults method of the Callable statement is called to move to the next ResultSet before getResultSet is called to return the next ResultSet See the Data Access and Change chapter on the syntax for declaring the cursor BEGIN ATOMIC DECLARE temp_zero DATE DECLARE result CURSOR WITH RETURN FOR SELECT FROM INFORMATION_SCHEMA TABLES FOR READ ONLY MORE SEAaESMENES OPEN result END 146 HyperSQL SQL Invoked Routines Handlers A handler declaration defines the course of action when an exception or warning is raised during the execution of the compound statement A compound statement may have one or more handler declarations These handlers become active when code execution enters the compound statemen
571. without the catalog file base name The files will be created with the names stored in the tar file and which you can see as described in the preceding section Encrypted Databases HyperSQL supports encrypted databases Encryption services use the Java Cryptography Extensions JCE and uses the ciphers installed with the JRE HyperSQL itself does not contain any cryptography code Three elements are involved in specifying the encryption method and key A cipher together with its configuration is identified by a string which includes the name of the cipher and optional parameters A provider is the fully qualified class name of the cipher provider A key is represented as a hexadecimal string Creating and Accessing an Encrypted Database First a key must be created for the desired cipher and configuration This is done by calling the function CRYPT KEY cipher spec provider If the default provider the built in JVM ciphers is used then NULL should be specified as the provider The CRYPT_KEY function returns a hexadecimal key The function call can be made in any HyperSQL database so long as the provider class is on the classpath This key can be used to create a new encrypted database Calls to this function always return different keys based on a generated random values As an example a call to CRYPT_KEY Blowfish null returned the string 604a6105889da65326bf35790a923932 To create a new database the URL below is used
572. ws If the old rows or new rows are referenced in the SQL statements in the trigger action they must have names The REFERENCING clause is used to give names to the old and new rows The clause REFERENCING OLD NEW TABLE is used for statement level triggers The clause REFERENCING OLD NEW ROW is used for row level triggers If the old rows or new rows are referenced in the SQL statements in the trigger action they must have names In the SQL statements the columns of the old or new rows are qualified with the specified names Trigger Condition The WHEN clause can specify a condition for the columns of the row that is being changed Using this clause you can simply avoid unnecessary trigger activation for rows that do not need it For UPDATE trigger you can specify a list of columns of the table If a list of columns is specified then if the UPDATE statement does not change the columns with SET clauses then the trigger is not activated at all Trigger Action in SQL The trigger action specifies what the trigger does when it is activated This is usually written as one or more SQL statements When a row level trigger is activated there is an OLD ROW or a NEW ROW or both An INSERT statement supplies a NEW ROW row to be inserted into a table A DELETE statement supplies an OLD ROW be deleted An UPDATE statement supplies both OLD ROW and NEW ROW that represent the updated rows before and after the update The REFERENCING clause gives na
573. ws statement SET FILES CACHE ROWS unsigned integer literal Sets the maximum number of rows of CACHED tables held in the memory cache The default is 50000 rows Only a user with the DBA role can execute this statement This is equivalent to the connection property hsqldb cache_rows SET FILES CACHE SIZE set files cache size statement 221 HyperSGL System Management set files cache size statement SET FILES CACHE SIZE unsigned integer literal Sets maximum amount of data of CACHED tables in kilobytes held in the memory cache The default is 10000 kilobytes Note the amount of memory used is larger than this amount which does not account for Java object size overheads Only a user with the DBA role can execute this statement This is equivalent to the connection property hsgldb cache size SET FILES DEFRAG set files defrag statement set files defrag statement SET FILES DEFRAG unsigned integer literal Sets the threshold for performing a DEFRAG during a checkpoint The unsigned integer literal is the percentage of abandoned space in the data file When a CHECKPOINT is performed either as a result of the Log file reaching the limit set by SET FILES LOG SIZE m or by the user issuing a CHECKPOINT command the amount of space abandoned since the database was opened is checked and if it is larger than specified percentage a CHECKPOINT DEFRAG is perform
574. xt step is to run CodeS witcher Example B 3 CodeSwitcher command line invocation java org hsqldb util CodeSwitcher JAVA2 The means the program works on the current directory all subdirectories are processed recursively JAVA2 means the code labelled with JAV A2 must be switched off Example B 4 Source code after CodeSwitcher processing ifdef JAVA2 pProperties store out hsqldb database i else 290 HyperSGL Building HyperSQL Jars pProperties save out hsqldb database endif For detailed information on the command line options run java org hsqldb util CodeSwitcher Usage examples can be found in the build xml file in the build directory Building Documentation The JavaDoc can be built simply by invoking the javadoc task target with Gradle or Ant The two Guides the one you are reading now plus the Utilities user guide are in DocBook XML source format To rebuild to PDF or one of the HTML output formats from the XML source run the Gradle target gen docs or the Ant target gen docs Instructions will be displayed In particular Obtain the HyperSQL documentation source We no longer include our Guide source files in our main distribution zip file in order to keep it small You may want to build from the trunk branch or the latest release tag You can download a static snapshot tarball from http hsqldb svn sourceforge net viewvc hsqldb base trunk or und
575. xt transaction in the current session HyperSQL does not yet support this feature LOCK TABLE lock table statement lt lock table statement gt LOCK TABLE lt table name gt READ WRITE lt table name gt READ WRITE In some circumstances where multiple simultaneous transactions are in progress it may be necessary to ensure a transaction consisting of several statements is completed without being terminated due to possible deadlock When this statement is executed it waits until it can obtain all the listed locks then returns If obtaining the locks would result in a deadlock an error is raised The SQL statements following this statements use the locks already obtained and obtain new locks if necessary and can proceed without waiting All the locks are released when a COMMIT or ROLLBACK statement is issued When the isolation level of a session is READ COMMITTED read locks are released immediately after the execution of the statement therefore you should use only WRITE locks in this mode Alternatively you can switch to the SERIALIZABLE isolation mode before locking the tables for the specific transaction that needs to finish consistently and without a deadlock It is best to execute this statement at the beginning of the transaction with the complete list of required read and write locks Currently this command does not have any effect when the database transaction control model is MVCC 37 Hype
576. y Name Default Description hsqldb result max memory rows storage of temporary results and tables in memory or on disk This property can be set to specify how many rows of each results or temporary table are stored in memory before the table is written to disk The default is zero and means data is always stored in memory If this setting is used it should be set above 1000 SET DATABASE DEFAULT RESULT MEMORY ROWS numeric value 236 HyperSGL Properties Table 12 38 Event Logging Name Default Description hsqldb applog application logging level The default level 0 indicates no logging Level results in minimal logging including any failures Level 2 indicates all events including ordinary events LEVEL 3 adds details of some of the normal operations The events are logged in a file ending with app log SET DATABASE EVENT LOG LEVEL 0 1 2 3 Table 12 39 SOL Logging Name Default Description hsqldb sqllog sql logging level can also be used to open an existing file database The default level 0 indicates no logging Level 1 currently logs only commits and rollbacks Level 2 currently logs all the SQL statements executed together with their parameter values Level 3 will be supported in the future The events are logged in a file ending with sql log This property applies to existing file databases as well as new databases SET DAT
577. y have a context that indicates some local time zone For example a database for college course timetables usually stores class dates and times without time zones This works because the location of the college is fixed and the time zone displacement is the same for all the values Even when the events take place in different time zones for example international flight times it is possible to store all the datetime information as references to a single time zone usually GMT For some databases it may be useful to store the time zone displacement together with each datetime value SQL s TIME WITH TIME ZONE and TIMESTAMP WITH TIME ZONE values include a time zone displacement value The time zone displacement is of the type INTERVAL HOUR TO MINUTE This data type is described in the next section The legal values are between 14 00 and 14 00 Operations on Datetime Types Theexpression datetime expression AT TIME ZONE time displacement evaluates to a datetime value representing exactly the same point of time in the specified time displacement The expression AT LOCAL is equivalent to AT TIME ZONE local time displacement If AT TIME ZONE is used with a datetime operand of type WITHOUT TIME ZONE the operand is first converted to a value of type WITH TIME ZONE at the session s time displacement then the specified time zone displacement is set for the value Therefore in these cases the final value depends on the time zone of the s
578. y ipv4 or ipv6 candidate address not matched above will be denied You put your file wherever it is convenient for you and specify that path with the property server acl or webserver acl in your server properties or webserver properties file depending on whether your listener instance is a Server or WebServer You can specify the ACL file path with an absolute or relative path If you use a relative path it must be relative to the properties file It s often convenient to name the ACL file acl txt in the same directory as your properties file and specify the property value as just acl txt This file name is intuitive and things will continue to work as expected if you move or copy the entire directory Warning If your Server or WebServer was started with a ac1 property changes afterwards to the ACL file will be picked up immediately by your listener instance You are advised to use the procedure below to prevent partial edits or mistakes from crippling your running server When you edit your ACL file it is both more convenient and more secure to test it as explained here before activating it You could of course test an ACL file by editing it in place then trying to connect to your listener with JDBC clients from various source addresses Besides being mightily laborious and boring with this method it is very easy to accidentally open access to all source addresses or to deny access to all users until you fix
579. y objects are returned as instances of java sql Array Cursor Declaration The DECLARE CURSOR statement is used within an SQL PROCEDURE body In the early releases of HyperSQL 2 0 the cursor is used only to return a result set from the procedure Therefore the cursor must be declared WITH RETURN and can only be READ ONLY DECLARE CURSOR declare cursor statement declare cursor DECLARE cursor name SENSITIVE INSENSITIVE ASENSITIVE SCROLL NO SCROLL CURSOR WITH HOLD WITHOUT HOLD WITH RETURN WITHOUT RETURN FOR query expression FOR READ ONLY UPDATE OF column name list The query expression is a SELECT statement or similar and is discussed in the rest of this chapter In the example below a cursor is declared for a SELECT statement It is later opened to create the result set The cursor is specified WITHOUT HOLD so the result set is not kept after a commit Use WITH HOLD to keep the result set Note that you need to declare the cursor WITH RETURN as it is returned by the CallableStatement DECLARE thiscursor SCROLL CURSOR WITHOUT HOLD WITH RETURN FOR SELECT FROM INFORMATION SCHEMA TABLES OPEN thiscursor Syntax Elements The syntax elements that can be used in data access and data change statements are described in this section The SQL Standard has a very extensive set of definitions for these elements
580. y usage speed and accessibility by different applications are influenced by how HyperSQL is deployed Mode of Operation The decision to run HyperSQL as a separate server process or as an in process database should be based on the following e When HyperSQL is run as a server on a separate machine it is isolated from hardware failures and crashes on the hosts running the application e When HyperSQL is run as a server on the same machine it is isolated from application crashes and memory leaks Server connections are slower than in process connections due to the overhead of streaming the data for each JDBC call e You can reduce client server traffic using SQL Stored procedures to reduce the number of JDBC execute calls During development it is better to use a Server with server silent false which displays the statements sent to the server on the console window Toimprove speed of execution for statements that are executed repeatedly reuse a parameterized PreparedStatement for the lifetime of the connections Tables TEXT tables are designed for special applications where the data has to be in an interchangeable format such as CSV comma separated values TEXT tables should not be used for routine storage of data MEMORY tables and CACHED tables are generally used for data storage The difference between the two is as follows The data for all MEMORY tables is read from the script file when the database is started an
581. ytable IF EXISTS are among such constructs Many print books cover SQL Standard syntax and can be consulted For a well written basic guide to SQL with examples you can also consult PostgreSQL Introduction and Concepts http www postgresql org files documentation books aw pgsql index html by Bruce Momjian which is available on the web Most of the core SQL coverage in the book applies also to HyperSQL There are some differences in keywords supported by one and not the other engine OUTER OID s etc or used differently IDENTITY SERIAL TRIGGER SEQUENCE etc In HyperSQL version 2 0 all features of JDBC4 that apply to the capabilities of HSQLDB are fully supported The relevant JDBC classes are thoroughly documented with additional clarifications and HyperSQL specific comments See the JavaDoc for the org hsqldb jdbc classes HyperSGL SQL Language SQL Data and Tables In an SQL system all significant data is stored in tables and sequence generators Therefore the first step in creating a database is defining the tables and their columns The SQL standard supports temporary tables which are for temporary data and permanent base tables which are for persistent data Temporary Tables Data in TEMPORARY tables is not saved and lasts only for the lifetime of the session The contents of each TEMP table is visible only from the session that is used to populate it HyperSQL supports two types of
582. ze of each row Result Set Memory Allocation By default all the rows in the result set are built in memory so very large result sets may not be possible to build A server mode databases releases the result set from the server memory once the database server has returned the result set An in process database releases the memory when the application program closes the java sql ResultSet object A server mode database requires additional memory for returning result sets as it converts the full result set into an array of bytes which is then transmitted to the client HyperSQL 2 0 supports disk based result sets The commands SET SESSION RESULT MEMORY ROWS lt integer gt and SET DATABASE DEFAULT RESULT MEMORY ROWS lt integer gt specify a threshold for the number of rows Results with row counts above the threshold are stored on disk These settings also apply to temporary tables views and subquery tables Disk based result sets slow down the database operations and should be used only when absolutely necessary perhaps with result sets that are larger than tens of thousands of rows In a server mode database when the setFetchSize method of the Statement interface is used to limit the number rows fetched the whole result is held by the engine and is returned to the JDBC ResultSet in blocks of rows of the specified fetch size 266 HyperSQL Deployment Guide Temporary Memory Use During Operations When UPDATE and D

HyperSQL User Guide - HyperSQL Database Engine (HSQLDB) 2.2

Contents

Download Pdf Manuals

Related Search

Related Contents