From: Florent GARIN <florent.garin_at_docdoku.com>
Date: Wed, 25 Jul 2007 10:05:20 +0200

 I have an object with a OneToMany association (actually it's a
composition in the UML sense) that is linked to an abstract entity
object. Thus, the collection association can contain any of the two
concret subtypes of the abstract entity class. The primary key of the
abstract
 The problem occurs when I want to cascade update this object. When
using the merge operation on the abstract entity