Constraints

I need to add a constraint to a table. I don't want to drop and recreate the table I just want to add a constraint.

The syntax I am using is as follows:
  ALTER TABLE tablename ADD CONSTRAINT
  pk_xxxx PRIMARY KEY (column1, column2);

I get the error message Invalid datatype on pk_xxxx. How do I creat a constraint on an existing table. Please reply to jeckles_at_westga.edu or jeanette_at_westga.edu.

Thanks for any assistance. Received on Sun Feb 18 1996 - 00:00:00 CET