Charlie What I use is Primary and Foreign Keys. I wouldn't suggest storing a null value as a primary key but use something that you know won't be input. For instance if the primary key is idnumber and it is integer then maybe make use -1
Buddy -----Original Message----- From: Charles Parks [mailto:[EMAIL PROTECTED]] Sent: Monday, February 03, 2003 8:48 AM To: [EMAIL PROTECTED] Subject: [RBASE-L] - Verify value or is null Is there a way to create a rule with a where clause that will allow entry to made into the table if the value exists in another table or if the value is null? I thought it would be something like this: WHERE EXISTS (SELECT Column1 FROM Table1 WHERE Table1.Column1 = Table2.Column2 ) or Table2.Column2 is null but that where clause is not working. Is possible to just store a null value in the lookup table or should I just set a default value in the primary table? Thanks, Charlie
