In addition ...
Before adding any CONSTRAINT(s) to existing Table/Column, the existing data MUST comply the rule(s) of adding such constraint. To resolve any data integrity issues ... try the following options: TALLY colname FROM tablename OR SELECT * FROM tablename WHERE colname IS NULL OR SELECT COUNT(*) INTO vRows INDIC ivRows FROM tablename WHERE colname IS NULL Hope that gives you some blues clues ... Very Best R:egards, Razzak.

