On Tue, 9 Apr 2002 13:28:04 -0400, Anthony Schmidt wrote:

>You can change the NOT NULL constraint for the Foreign Key after 
the fact. 

Tony is right, but before you do add a NOT NULL constraint to an 
existing  column, first be sure there ARE no nulls in the data.

In general, any time you want to establish or change a PRIMARY KEY, 
UNIQUE KEY, FOREIGN KEY, or NOT NULL constraint definition 
where data already exists in the affected columns, requires you to 
audit the data carefully first, to be sure the existing data would have 
been allowed into the table if that constraint had been in effect. You 
can break your database if you try to add a constraint to non-
conforming data.

Bill





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