Hi..

I'm having a problem with onDelete method in Hibernate 2.1. My onDelete method needs to do a query with other entities, with cause an autoflush.
As a consequence of this, the parent entity is deleted before I can delete the child entities. The full stacktrace below.
The tables "recurso" and "agenda" are the parent entity (joined-subclass in this case). The onDelete method of Recurso is



Am I doing something wrong, or is this a bug?

Thanks,
Robson Paniago

21:11:49,385 INFO [STDOUT] Hibernate: delete from recurso where id=?
21:11:49,385 INFO [STDOUT] Hibernate: delete from agenda where id=?
21:11:49,385 WARN [JDBCExceptionReporter] SQL Error: 350, SQLState: 23000
21:11:49,385 ERROR [JDBCExceptionReporter] [350]: Referential integrity violated:FKB307E11599C04A2E,CAMPUS,EVENTO
21:11:49,385 ERROR [JDBCExceptionReporter] Could not synchronize database state with session
com.sap.dbtech.jdbc.exceptions.DatabaseException: [350]: Referential integrity violated:FKB307E11599C04A2E,CAMPUS,EVENTO
at com.sap.dbtech.jdbc.packet.ReplyPacket.createException(ReplyPacket.java:69)
at com.sap.dbtech.jdbc.ConnectionSapDB.throwSQLError(ConnectionSapDB.java:763)
at com.sap.dbtech.jdbc.ConnectionSapDB.execute(ConnectionSapDB.java:429)
at com.sap.dbtech.jdbc.ConnectionSapDB.execute(ConnectionSapDB.java:320)
at com.sap.dbtech.jdbc.CallableStatementSapDB.execute(CallableStatementSapDB.java:380)
at com.sap.dbtech.jdbc.CallableStatementSapDB.execute(CallableStatementSapDB.java:289)
at com.sap.dbtech.jdbc.CallableStatementSapDB.executeUpdate(CallableStatementSapDB.java:697)
at org.jboss.resource.adapter.jdbc.WrappedPreparedStatement.executeUpdate(WrappedPreparedStatement.java:308)
at net.sf.hibernate.persister.NormalizedEntityPersister.delete(NormalizedEntityPersister.java:606)
at net.sf.hibernate.impl.ScheduledDeletion.execute(ScheduledDeletion.java:22)
at net.sf.hibernate.impl.SessionImpl.executeAll(SessionImpl.java:2100)
at net.sf.hibernate.impl.SessionImpl.execute(SessionImpl.java:2066)
at net.sf.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:1566)
at net.sf.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:1372)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1332)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1322)
at net.sf.hibernate.impl.SessionImpl.delete(SessionImpl.java:1457)
at net.sf.hibernate.impl.SessionImpl.delete(SessionImpl.java:1447)
at unb.campusvirtual.ejb.dataobjects.Recurso.onDelete(Recurso.java:229)
at unb.campusvirtual.ejb.dataobjects.Agenda.onDelete(Agenda.java:54)
at net.sf.hibernate.impl.SessionImpl.delete(SessionImpl.java:977)
at unb.campusvirtual.ejb.impl.ControleGerenciamentoRecursosBean.excluiRecurso(ControleGerenciamentoRecursosBean.java:189)
....

I dont think it is intended to to a delete query in an onDelete of another entity. Can't you use cascade="delete" for this?

This is only a part of the delete logic, this part could really be solved by using cascade. But after this, I need to update some other objects, and, in this case, I really need to do a query.

I can work around this problem by not using Hibernate's Lifecycle interface, but I think that using it I get a cleaner code (I do not need to recurse for every child, for example).

Thanks,
Robson Paniago

Hi..

I just checked with Hibernate 2.1 and cascade="all-delete-orphan", it worked.

However, using my old onDelete() implementation on class Agenda, it did not work (it tried to delete the parent first), only using the cascade="all-delete-orphan" in the .hbm.xml file worked. My onDelete() was:



Is this supposed to work, right?

Thanks
Robson Paniago

I had the same problem with onDelete. I got rid of the exception by flushing the session, to force the sql deleting the children to be executed before that deleting the parent. This works when I delete 1 parent at time.

But when I delete many parents with: session.delete("from Parent") I get the following exception:

java.lang.IllegalArgumentException: fromIndex(1) > toIndex(0)
at java.util.SubList.<init>(AbstractList.java:706)
at java.util.RandomAccessSubList.<init>(AbstractList.java:860)
at java.util.AbstractList.subList(AbstractList.java:569)
at net.sf.hibernate.impl.SessionImpl.doDelete(SessionImpl.java:1155)
at net.sf.hibernate.impl.SessionImpl.delete(SessionImpl.java:1114)


Hibernate 2.1 reference documentation specifies:
"onSave(), onDelete() and onUpdate() may be used to cascade saves and deletions of dependent objects. This is an alternative to declaring cascaded operations in the mapping file."

Is there any best practice/guideline on how to implement cascade delete in onDelete method.

Thank you,

mota

This is a change in behavior between 2.1 and 2.1.1. Basically we do not allow flushing from onDelete(). You can do session.setFlushMode(FlushMode.COMMIT) to disable the flush that occurs before query execution.

P.S. I would never, ever do this kind of stuff in on onDelete() method. It is waay to complex....