Hi all... as part of the sharing information in this forum. Here we go.... to resolve this problem is to ensure the loop_serv description of the loop table with loop_id=0 must be blank i.e. similar to the union select statement. Earlier we have to do the count of the view SERV vs COMPONENT. Then drop view and rerun the create view SERV statement. Since we have make the loop_serv description of the loop table where its loop_id=0 a blank then the VIEW union select will do nothing once we execute hence problem solve. Whereby before when the loop_serv description of the loop table isn't blank then the union select statement will just append another record with the SERV cmpnt_id=0 and the SERV loop_id=0 hence the invalid database structure error occurs due to a mismatch between the record SERV and COMPONENT.