WITH CHECK ADD CONSTRAINT followed by CHECK CONSTRAINT vs. ADD CONSTRAINT

Question

I\'m looking at the AdventureWorks sample database for SQL Server 2008, and I see in their creation scripts that they tend to use the following:

ALTER TABLE          


        

Answer 1

Foreign key and check constraints have the concept of being trusted or untrusted, as well as being enabled and disabled. See the MSDN page for ALTER TABLE for full details.

WITH CHECK is the default for adding new foreign key and check constraints, WITH NOCHECK is the default for re-enabling disabled foreign key and check constraints. It's important to be aware of the difference.

Having said that, any apparently redundant statements generated by utilities are simply there for safety and/or ease of coding. Don't worry about them.