Re: Implementing complicated constraints

From: Tony Andrews <andrewst_at_onetel.com>
Date: 28 Sep 2004 08:11:44 -0700
Message-ID: <1096384303.973082.269160@k17g2000odb.googlegroups.com>

Mark D Powell wrote:
> The fact that the ATXT column of A needs to be unique in relation to
> the CID value which does not appear in A indicates a relational
design
> flaw in your tables.

I don't agree with that. It is just a constraint of a complexity that Oracle cannot handle via constraints. If Oracle implemented the ANSI SQL assertion syntax then the constraint could be implemented without having to have the CID denormalised into the A table.

Of course, having the CID in the A table is a viable work-around, but that doesn't mean there was a relational design flaw before. Received on Tue Sep 28 2004 - 10:11:44 CDT