Have you checked whether the correct foreign keys are in place in the database? If not, have you tried to drop the tables and allow Hibernate (which I assume you're using) to generate the tables again? On a side note, a few non related tips for you: 1. You don't need an explicit constructor if the sole constructor is public and has no arguments. Calling super() is useless if the class only extends java.lang.Object. 2. When defining relationships, you don't need to specify targetEntity when using generics. 3. You don't EVER have to specify strategy = GenerationType.AUTO, since it's the default anyway. 4. Always use English for variable and method names. Makes your software more consistent and maintainable. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4020083#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...