Re: Modelling Disjoint Subtypes
From: Joe Thurbon <usenet_at_thurbon.com>
Date: Thu, 22 Mar 2007 21:43:50 GMT
Message-ID: <qMCMh.506$M.7_at_news-server.bigpond.net.au>
>
> You are barking up the wrong tree. If at all possible, the only
> constraints one should have are foreign key references. What exactly
> prevents one from using a foreign key constraint to enforce the disjoint
> requirement?
Date: Thu, 22 Mar 2007 21:43:50 GMT
Message-ID: <qMCMh.506$M.7_at_news-server.bigpond.net.au>
Bob Badour wrote:
> Joe Thurbon wrote:
>> >> Am I just barking up the wrong tree? Would you like to tell me the >> answer?
>
> You are barking up the wrong tree. If at all possible, the only
> constraints one should have are foreign key references. What exactly
> prevents one from using a foreign key constraint to enforce the disjoint
> requirement?
then,
I want to ensure is that for each value of the attribute K appearing in
COMMON, that value appears as the value for K in at most 1 of the tables
SUBTYPE1...SUBTYPEN.
Cheers,
Joe
Received on Thu Mar 22 2007 - 22:43:50 CET