Tim, thanks a lot for your answer! It seems as if this solution only works in a bi-directional one-to-one relation? Is that true? In my case, I don´t have the "Parent"-object in my "Child" as a back-reference. So is it a "must-requirement" to have a bi-directional relation or is there also a way for a uni-directional relation? Thanks for help Thomas View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4124693#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...