Hi, i have a problem with persisting entities and get ConstraintViolationExceptions . In Hibernate, there is a saveOrUpdate feature that is missing in the EJB 3.0 Persistence specification, as far as I know merge is not the same (and that didn't work for me anyways). I have a Text-Object that contains Sentence Objects which in turn contain words. Now I don't want to have double entries of certain words but rather e.g. persisting "This car is his car" should not add two times "car" into the DB. To avoid that, I tried using the actual token (String token of Word Object) as the PK but that results in ConstraintViolationExceptions... Any clues? Thanks, Joey View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3975547#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...