Referential Integrity.

From: "Wm(dot) G(dot) Urquhart" <wgu(at)wurquhart(dot)co(dot)uk>
To: PostgreSQL General Forum <pgsql-general(at)postgresql(dot)org>
Subject: Referential Integrity.
Date: 2002-05-20 11:53:24
Message-ID: Pine.LNX.4.44.0205201243330.13618-100000@mailer.wurquhart.co.uk
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Hi All,

After yesterday's disaster I've taken this opportunity to rebuild by
database from the ground up. As part of this I want to be able to set a
column to have a default of 0 (easy enough) but this column is a Foreign
Key to another table whos referenced column value starts at 1.

Is there anyway I can write a FK Constraint that will allow this? I don't
want to have to enter a row in the referenced table since since it in turn
has not null constraints on it.

I really want a way to allow 0 as a legitimate value, to assist in the
predicates of a SELECT. It is possible to get to and modify the code that
PostgreSQL creates to enforce this I assume via CREATE CONSTRAINT TRIGGER?

Any help would be appreciated.

--
Regards,

Wm. G. Urquhart
Custom Software Solutions
http://www.wurquhart.co.uk

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Wm. G. Urquhart 2002-05-20 13:07:01 Further thoughts on Referential Integrity
Previous Message Gareth Kirwan 2002-05-20 11:53:01 Interval to number