can't delete a taskinstance from my database

[galvino]

hi, i want to delete a task instance from my database (mysql).

this is my source code:

Connection connection=jbpmContext.getConnection();
 Statement statement=connection.createStatement();

// écriture de la requête de recherche
 request="DELETE "
 + "FROM jbpm_taskinstance "
 + "WHERE id_='"
 + taskInstanceId + "'";

// execution de la requête
 statement.execute(request);

// fermeture de la connection à la base de données
 statement.close();
 connection.close();

but i doesn't work because, i think it doesn't execute query :

statement.execute(request);

i tried

statement.executeUpDate(request);

but i have the same error:

com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: Cannot delete or update a parent row: a foreign key constraint fails (`paolo/jbpm_log`, CONSTRAINT `FK_LOG_TASKINST` FOREIGN KEY (`TASKINSTANCE_`) REFERENCES `jbpm_taskinstance` (`ID_`))
 at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:931)
 at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2934)
 at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1616)
 at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1708)
 at com.mysql.jdbc.Connection.execSQL(Connection.java:3249)
 at com.mysql.jdbc.Connection.execSQL(Connection.java:3178)
 at com.mysql.jdbc.Statement.execute(Statement.java:711)
 at BesoinJBpm.deleteTaskInstance(BesoinJBpm.java:361)
 at BesoinJBpm.Test(BesoinJBpm.java:55)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at junit.framework.TestCase.runTest(TestCase.java:154)
 at junit.framework.TestCase.runBare(TestCase.java:127)
 at junit.framework.TestResult$1.protect(TestResult.java:106)
 at junit.framework.TestResult.runProtected(TestResult.java:124)
 at junit.framework.TestResult.run(TestResult.java:109)
 at junit.framework.TestCase.run(TestCase.java:118)
 at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:128)
 at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)

how can i delete this ?

[vtysh]

Why do you use sql not hql? See how it is done in jbpm sources.

[vtysh]

And i think you can't delete directly TaskInstance row, because task instance has relationships with other objects (see TaskInstance.hbm.xml)

[galvino]

it too dificult for me.
i don't understand the xml file taskinstance.hbm.xml.
what should i change into this file in order to delete a taskinstance ?

[kukeltje]

than learn it... this is 2007 you know.... It took me one day to learn the basics....

[estaub]

galvino,
In case it isn't obvious ... you should be reading up on Hibernate. The online documentation is good, and so is the book.