I have a simple hierarchy mapped as <subclass>es:

Parent
- Child 1
-- Sub Child
- Child 2
- Child 3

Is it possible to transform an instance of Child 1 into an instance of Sub Child? Or Child 1 -> Child 3?

We have a product class hierarchy in which a user can switch between an inventory and non-inventory product class. Of course there are some business ramifications we are dealing with, I just am wondering if there is a way to do this with the framework rather than resorting to direct JDBC calls to change the discriminator value?

Chris.....

What you want is a way to transform an Apple into a Orange just because they are both fruits.
I strongly suspect you design an incorrect OO hierarchy. The many-to-one tree structure is probably more appropriate in your case

This is rather more a oo-problem than a hibernate problem. If you can solve the problem of having objects dynamically change types in your class model (which is not quite easy with java), you should have no problems mapping this with hibernate.

I have the same question for my own application. I have various user types: admin (my team/me!), reseller, company, manager and client. I might want to change one from one type to another. I'm using subclass or joined-subclass for each user type.

I don't care of the client has to logout and login again for the change to take effect.

Regards,
David

If you decide to listen to Emmanuel, get your hands on copy of the Design Patterns book by the Gang of Four (google it or look an amazon). Read and internalize the first couple of chapters then look up the state and strategy patterns.