Re: Schema Relationship Question

From: David Portas <>
Date: Sat, 6 Oct 2007 19:55:13 +0100
Message-ID: <>

"JamesHoward" <> wrote in message
> Thanks for the answers. It sounds like the best solution between
> allowed pairings and disallowed pairings comes down to how much data
> you will have to enter. If one of those is dense in a large possible
> data space then it wouldn't be ideal to enter that much manual data.
> I think I am going to go for the disallowed pairings in this case as
> it is less data to enter.

Check the features of your DBMS product first. Some SQL DBMSs don't support multi-table constraints other than foreign keys. If that's the case with your DBMS then you may have to resort to procedural code to enforce the rule about disallowed pairings. On the other hand, the rule for valid pairings CAN be implemented using only a foreign key.

David Portas 
Received on Sat Oct 06 2007 - 20:55:13 CEST

Original text of this message