Re: foreign key constraint versus referential integrity constraint
Date: Wed, 21 Oct 2009 09:18:25 -0700 (PDT)
> I prefer the term "inclusion dependency": projection of one relation
> (that is rvRedemptions v [CouponID]) is a supepersetset of projection
> of the other (i.e. rvOrders v [CouponID]). I thought that all three
> terms are the same; perhaps with foreign key constraint adding some
> insignificant matter, like the "smaller" set being unique.
BTW, one limitation of foreign keys which I find particularly annoying is that they only work when we're talking about base tables whereas I've already bumped a few times into a situation where I would have liked to constrain (on) the contents of a view. That sometimes happens when you have to go beyond 3NF or you're working with a conceptual model which allows multiple inheritance and/or union types. Do you happen to know whether this sort of thing is formally covered by the concept of inclusion dependency?
-- SampoReceived on Wed Oct 21 2009 - 18:18:25 CEST