Save the transient instance before flushing

rosswilliamdrew · **Posted:** Fri Feb 20, 2009 6:39 am

I've had a look to see if anyone has came across this problem before and indeed they have, it seems everyones problem was fixed with the addition of cascade="save-update" though, this is not the case with mine.
Thanks in advance for any help :D

Hibernate version:3.2.6

Mapping documents:

Code:

<hibernate-mapping>
    <class name="Event" table="EVENTS">
        <id name="id" column="EVENT_ID" unsaved-value="-1">
            <generator class="native"/>
        </id>
        
        <property name="date" type="timestamp" column="EVENT_DATE"/>
        <property name="title"/>
        
      <set name="clients" table="CLIENTS" cascade="save-update">
         <key column="id" />
         <one-to-many class="Client"  />
      </set>
      
        <property name="requiredResources" type="ResourcesUserType" column="resourceNames" />
    </class>

    <class name="Client" table="Client">
        <id name="id" column="CLIENT_ID" unsaved-value="-1">
            <generator class="native"/>
        </id>
        <property name="name"/>
    </class>

    <class name="Resource" table="Resource">
        <id name="id" column="RESOURCE_ID" unsaved-value="-1">
            <generator class="native"/>
        </id>
        <property name="name"/>
    </class>
</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():

Code:

    private void createAndStoreEvent(String title, Date theDate, List<Client> clients, List<Resource> resources) {

        Session session = HibernateUtil.getSessionFactory().getCurrentSession();

        session.beginTransaction();

        Event theEvent = new Event();
         theEvent.setTitle(title);
         theEvent.setDate(theDate);
         theEvent.setClients(clients);
         theEvent.setRequiredResources(resources);

        session.save(theEvent);

        session.getTransaction().commit();
    }

Full stack trace of any exception that occurs:

Code:

578 [main] ERROR org.hibernate.event.def.AbstractFlushingEventListener - Could not synchronize database state with session
org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: Client
   at org.hibernate.engine.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:242)
   at org.hibernate.type.EntityType.getIdentifier(EntityType.java:430)
   at org.hibernate.type.ManyToOneType.nullSafeSet(ManyToOneType.java:101)
   at org.hibernate.persister.collection.AbstractCollectionPersister.writeElement(AbstractCollectionPersister.java:777)
   at org.hibernate.persister.collection.AbstractCollectionPersister.recreate(AbstractCollectionPersister.java:1165)
   at org.hibernate.action.CollectionRecreateAction.execute(CollectionRecreateAction.java:58)
   at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:171)
   at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
   at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
   at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
   at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)
   at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
   at EventManager.createAndStoreEvent(EventManager.java:61)
   at EventManager.main(EventManager.java:29)
Exception in thread "main" org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: Client
   at org.hibernate.engine.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:242)
   at org.hibernate.type.EntityType.getIdentifier(EntityType.java:430)
   at org.hibernate.type.ManyToOneType.nullSafeSet(ManyToOneType.java:101)
   at org.hibernate.persister.collection.AbstractCollectionPersister.writeElement(AbstractCollectionPersister.java:777)
   at org.hibernate.persister.collection.AbstractCollectionPersister.recreate(AbstractCollectionPersister.java:1165)
   at org.hibernate.action.CollectionRecreateAction.execute(CollectionRecreateAction.java:58)
   at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:171)
   at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
   at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
   at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
   at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)
   at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
   at EventManager.createAndStoreEvent(EventManager.java:61)
   at EventManager.main(EventManager.java:29)

Name and version of the database you are using:PostGres

The generated SQL (show_sql=true):

Code:

Hibernate: insert into EVENTS (EVENT_ID, EVENT_DATE, title, resourceNames) values (null, ?, ?, ?)
org.hsqldb.jdbc.jdbcPreparedStatement@adb1d4[sql=[insert into EVENTS (EVENT_ID, EVENT_DATE, title, resourceNames) values (null, ?, ?, ?)], parameters=[[2009-02-20 10:36:15.587], [StoreTest], [null]]]
Hibernate: call identity()
Hibernate: update Client set id=? where CLIENT_ID=?

[/code]

mcbi4kh2 · **Joined:** Thu Jun 12, 2008 10:48 am **Posts:** 24

Do you not need a set of resources in the same way you have a set of clients in your mapping file?

rosswilliamdrew · **Posted:** Fri Feb 20, 2009 7:12 am

I see what you mean but no, it's a legacy database in which there is one field which holds a list of Resource names which are then split and individually retrieved from the Resource table, awkward I know but apparently the idea was to cut down JOINs.

The problem I'm having though seems to be with the Client association.

jansi · **Posted:** Fri Feb 20, 2009 8:31 am

Can you kindly change id in key tag to event id as it shown below,

<set name="clients" table="CLIENTS" cascade="save-update">
<key column="EVENT_ID" />
<one-to-many class="Client" />
</set>

littypreethkr · **Posted:** Fri Feb 20, 2009 9:09 am

jansi wrote:

Can you kindly change id in key tag to event id

No I dont think this is the issue here. The key tag should have value "id" if that is the foriegnkey column name or "event_id" if thats the foreign key column name.

But the issue is with your unsaved-value="-1" attribute. You have specified that the unsaved-value is -1. But assuming that the id properties are long or int, whenever you create a Event or Client object the id property will get initialized to 0. So when you are saving this object Hibernate will see that the id field is 0 != -1; so it assumes that the object you provide is a transient object having a corresponding row in the DB with primary key 0. So it will just issue an update for the Client object and not an insert.

So if you put unsaved-value="0" in the mapping then it should work fine. Or you initialize your POJO id fields with -1.

rosswilliamdrew · **Posted:** Fri Feb 20, 2009 9:12 am

Ok, turns out that my problem was the hbm.xml files weren't being accessed by the .class files properly, not a Hibernate problem at all.
But thanks for the EVENT_ID. I never even noticed that I'd did that

rosswilliamdrew · **Posted:** Fri Feb 20, 2009 9:18 am

littypreethkr wrote:

So if you put unsaved-value="0" in the mapping then it should work fine. Or you initialize your POJO id fields with -1.

As I said, the issue was with my project directories rather than hibernate. Useful information though thanks

Milo · **Joined:** Thu Aug 20, 2009 3:00 am **Posts:** 11

I had this message "org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing com.vetmanager.database.animal.Animal" from this pease of code:

Code:

      
if((consult==null || consult.getId()==null) && animal!=null) {
  // select newest consult for this an animal
  EntityManager entityManager = getEntityManagerFactory().createEntityManager();
  Query query = entityManager.createQuery("FROM Consult WHERE animal = :animal ORDER BY consultDate DESC");
  query.setParameter("animal", animal);
  ArrayList<Consult> consults = (ArrayList<Consult>)query.getResultList();                  <=== Line where the exception was raised
  if(consults.size()>0) {
    setConsult(consults.get(0));
  }
    entityManager.close();
  }
}

But animal is just a new object and completely empty. It seams that Hibernate/Persistence checks if the id==null. If so it desides that the object must be transient. So changing the code slightly fixed it:

Code:

if((consult==null || consult.getId()==null) && animal!=null && animal.getId()!=null) {
...

So in my case it had nothing to do with database issues but just with that I used an empty object without a valid id.

Hope this helps anybody :)