if i remember correctly, the @OneToMany relationship will, by default, create a table for the "many" side which will contain a foreign key referencing the "one" side. so, since messageId is the PK for CommsMessage the table representing CommsMessageRecipient will have two columns named messageId: one as the FK referencing CommsMessge and another as part of its own PK. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4060619#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...