Thank you very much for this hint. But as far as I can see, I would have to define a DiscriminatorColumn in my superclass (AbstractBalance) from which I can decide between one of my inheritances, for every id in this table But in my case both tables (BalanceA and BalanceB) are referencing to the same id of the superclass and it is possible that either only an object of BalanceB or instances of both objects can exist. This is dependend of an existing entry in the related tables. Can someone give me an idea how to solve that? Thanks Thomas View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4001730#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...