Putting a null rule on the column may be appropriate if having a value in the column is a requirement. If the data in the column is optional (as in somtinme you would like to leave the field blank.) then you do not want to apply the rule.
The FK means, IF you are going to have a value in the column, that value MUST exist in the PK column first. Fred -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Jim Blackburn Sent: Tuesday, November 27, 2001 1:00 PM To: Rbase-L@Sonetmail. Com Subject: Constraints I have a table with a Foreign Key that references a Primary Key in another table. I was just surprised to see that the Foreign Key field can be changed to null. Is a not null rule the appropriate way to ensure the field is valid? Thanks for any advice, Jim Blackburn Kodiak
