Why can not insert into database

zhb402 · **Joined:** Thu Nov 23, 2006 5:00 pm **Posts:** 19

I have the following code:

Code:

   session.save(gp1);
   session.flush();
   session.clear();
    session.close();

               session = sessionFactory.openSession();
    tracks = listGroupRelation(session);
                iiter = tracks.listIterator();
   while ( iiter.hasNext() ) {
     GroupRelation aTrack = (GroupRelation)iiter.next();
     if (aTrack.contains(gp1))
     {
                 System.out.println("The node exist no2");  //check whether the database changed
     }

Where, gp1 is the object instance I want to save to database. I can see, there is printout "The node exist no2" for the above code. However, when I check the database, the gp1 does not be inserted into db. Can anybody tell me why this happens?

halconGT · **Posted:** Wed Dec 20, 2006 6:09 pm

turn on the echo of sql statements generated on your configuration file to show the sql statement generated. It seems your sql instruction isn't behind a session context.

zhb402 · **Joined:** Thu Nov 23, 2006 5:00 pm **Posts:** 19

No. It is on a session.
Actually, I just got the solution, because it is not in a transaction. The save() must include in a transaction() and commit().

However, when I do the delete operation, another exception produced:

[java] org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [com.bear.test1.GroupRelation#33775140]
[java] at org.hibernate.engine.StatefulPersistenceContext.checkUniqueness(StatefulPersistenceContext.java:556)
[java] at orgg.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventLis
tener.java:88)
[java] at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventLis
tener.java:49)
[java] at org.hibernate.impl.SessionImpl.fireDelete(SessionImpl.java:766)
[java] at org.hibernate.impl.SessionImpl.delete(SessionImpl.java:744)
[java] at com.bear.test1.QueryTest.initDirectedGraph(Unknown Source)
[java] at com.bear.test1.QueryTest.main(Unknown Source)
[java] Exception in thread "main"
[java] Java Result: 1

Who knows why this happen?

The code is almost the same thing, except I replace the save with delete. This time, I include the delete in a transaction() and commit().

halconGT · **Posted:** Wed Dec 20, 2006 6:59 pm

how are you ensuring the object identity?, to say how do you attach the objet to delete to session environment?

zhb402 · **Joined:** Thu Nov 23, 2006 5:00 pm **Posts:** 19

I use the following code:

Code:

//gp1 is the object I want to delete
        //tracks is the collection of mapping objects
    Transaction tranc = session.beginTransaction();
    if (tracks.contains(gp1))
   {
        System.out.println("contrain the result");
                }  
                     tracks.add(gp1);
        gp1 = tracks.get(index);
       session.delete(gp1);
    tranc.commit();
   session.flush();
   session.clear();
    session.close();

I just found the error, and it is the " tracks.add(gp1);" This is another test I added and I forget to remove it.
After I remove this, it works.

zhb402 · **Joined:** Thu Nov 23, 2006 5:00 pm **Posts:** 19

Now, I have a new problem for saveOrUpdate() method. This time, I want use saveOrUpdate() to insert into table.

Code:

Transaction tranc = session.beginTransaction();
session.saveOrUpdate(gp1);
System.out.println("go to here");
tranc.commit();

The "go to here" can be printout. However, when I do commit, it produced the following exception:

[java] org.hibernate.StaleStateException: Batch update returned unexpected row count from updat
e [0]; actual row count: 0; expected: 1
[java] at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:6
1)
[java] at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:
46)
[java] at org.hibernate.jdbc.NonBatchingBatcher.addToBatch(NonBatchingBatcher.java:24)
[java] at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersi
ster.java:2353)
[java] at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEnt
ityPersister.java:2257)
[java] at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersi
ster.java:2557)
[java] at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:92)
[java] at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:248)
[java] at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:232)
[java] at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:140)
[java] at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractF
lushingEventListener.java:298)
[java] at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListen
er.java:27)
[java] at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
[java] at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
[java] at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
[java] at com.bear.test1.QueryTest.initDirectedGraph(Unknown Source)
[java] at com.bear.test1.QueryTest.main(Unknown Source)
[java] Exception in thread "main"
[java] Java Result: 1

Why I can not use saveOrUpdate()? The id for the mapping xml, I set unsaved-value="null". Is it right?