Hi, Andy, Thanks for answering. What I expect is when I run "select t from
SMSMessageAbstract t where
t.creationDate>=:p_startDate ", I should be able to get result without exception like org.datanucleus.exceptions.NucleusUserException: Unable to find table for primary t.creationDate since the class izone.adams.model.messaging.SMSMessageAbstract is managed in multiple tables. Look at the the exception, it concerns about how to handle multiple morph(return all kind of subclass object of SMSMessageAbstract ).