Hi, I definde an entitybean with a uniqueConstraint like this | @Table | (name="usergroup", | uniqueConstraints = {@UniqueConstraint(columnNames={"mandantID", "name"})} | ) | public class BenutzerGruppe implements Serializable | { private long mSid; | private long mMandantID; | private String mName; I cannot see any effect in the database and it is possible to insert entities which violates the constraint. I´m using MySQL 5.0.24a Do I have to do anything more than using the annotaion in the entitybeandefinition? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4019802#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...