Re: Constraints and Functional Dependencies
Date: Sat, 24 Feb 2007 14:41:36 GMT
> With such a system, a relation R with attribute a (which I will
> write as R(a)) having a as a foreign key into S(b) is expressed
> as follows:
> forall R(a): exists S(b): a = b
> So we can express foreign keys this way.
p Received on Sat Feb 24 2007 - 15:41:36 CET