Hello,
My setup is JBoss 3.2.1, with Hibernate 2.03 installed as an MBean running against MS SQLServer 8. All Hibernate calls are actioned through Session EJBs with CMT, the Hibernate session being closed at the end of each EJB method invocation.

We've got a one-to-one relationship set up as follows:




What we're attempting to do is add new (transient) Account to an already existing Customer, and then save it via a session bean call. What actually happens is that Hibernate attempts to create a new instance of Customer on the database, which fails because of the unique constraint on Customer.name. If the constraint is remove we get multiple duplicate rows.

Our current none-working code looks like this:



I've tried various combinations of composition and bean saving, but mthing has made any difference. Can anyone shed any light on this, please?

Will

sounds like the typical kind of thing that happens due to a bad unsaved-value mapping

Gavin,

thanks for your reply. Can you point me in the direction of a good unsaved-value mapping?

Will

This is not a bad unsaved-value problem.
I use the XY.hbm.xml from net.sf.hibernate.test where the unsaved-value for the id is set to "0" explicitly. I got the same problem.


Using the XY.hbm.xml in the net.sf.hibernate.test package as example,
when I associate a X object for a Y object loaded in previous closed session, and save the X, the new session can not detect that the Y is already an object from database. It always generates a new Y object by inserting a row into the database.
I think this is a bug. If it is a feature, what is the consideration after
this feature?

Thanks.


I have the following code:
----------------------coding-----------------
SessionFactory sf= config.buildSessionFactory();
Session session= sf.openSession();

//---- loading a object and close the session.
Y y=(Y)session.load(Y.class, new Long(1));
session.close();

// associate a new X object for the loaded Y.
X x=new X();
x.setY(y);
y.setTheX(x);

//----- open a new session.
session=sf.openSession();
Transaction tx=session.beginTransaction();
// critical line.
/*
If I call the saveOrUpdate(y), the session correctly detected
that a new X object is created, and insert a row into X
If I call the saveOrUpdate(x), the session always first create a
new Y object (by inserting a row in Y) and insert a row into X.

In my mind, the session should detect that the Y object is a
persistent object from previouse session and it should not generate a new Y object.

Is this a bug or a feature?
If it is a feature, what is the consideration for this feature?
*/
session.saveOrUpdate(y);
tx.commit();
session.close();
---------------------------code-------------------

Thanks

OK, its true that ForeignGenerator does not handle detached objects correctly. I'll see about fixing this.