No, it's uni-directional. So in the part bean I have the key-fields marked with id and so on. No hint that part is used in a relation. @Entity | @IdClass(value=Part.PK.class) | @Table(name="part") | public class Part implements Serializable | { | @Id | @Column(name="msghd_serial") | private Integer msghdSerial; | | @Id | @Column(name="part_no") | private Integer partNo; | ... | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4084259#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...