So you call persist if you are trying to add an entity to the database, update for one that is already there. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4026856#4026856 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4026856