----- "Steve Ebersole" <steve(a)hibernate.org&gt; escreveu: Not only that: they even have a very specific error message about it :-) Look for "SQLSTATE: 42831". One more reference: http://publib.boulder.ibm.com/infocenter/cscv/v10r1/index.jsp?topic=/com.... "Just as in CREATE TABLE, if the column definition includes a unique or primary key constraint, the column cannot contain null values, so the NOT NULL attribute must also be specified (SQLSTATE 42831)." Ok, I'll commit it. And you also won Czech beer or Moravian wine. Make your choice :-) - Juca.