Should relationships be created in the front end, back end or both?
The backend. Only. They will be inherited by any frontend using that
backend; but only when the relationships are in the database
containing the tables can they be enforced. A relationship defined in
the frontend cannot be enforced (someone could open the backend
directly) and serves only to provide a default join for queries - it
doesn't protect your data.
John W. Vinson[MVP]
