Check constraints are supported in all of the major DBMS products, including DB2, Oracle, and SQL Server. But they are too-often ignored and not implemented in production databases. Properly defined, ...

So, it is a good physical database design practice to implement referential integrity using database constraints. Ignoring the relationships does not eliminate the business requirement. Proper ...

By using cascading referential integrity constraints, you can define the actions that SQL Server 2005 takes when a user tries to delete or update a key to which existing foreign keys point.