Re: brain-teaser with CONSTRAINT - any SQL experts?

From: Keary Suska <hierophant(at)pcisys(dot)net>
To: Postgres General <pgsql-general(at)postgresql(dot)org>
Subject: Re: brain-teaser with CONSTRAINT - any SQL experts?
Date: 2005-10-09 17:54:18
Message-ID: BF6EB56A.22218%hierophant@pcisys.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

on 10/8/05 11:36 PM, mileskeaton(at)gmail(dot)com purportedly said:

> I know it's tempting to say, "just link a separate table for the book
> and don't store the book name" but let's just pretend that's not an
> option - because I'm not actually dealing with books : I just made up
> this simplified version of something at work, where we can't change
> the table : both isbn and name MUST be in the table, and what I'm
> trying to do is put a CONSTRAINT on the table definition to protect
> against user error, by making sure that any entered isbn is only tied
> to one book-name in that table.

I would create a multi-column unique index on the table. This should solve
the problem mentioned although you may still have an integrity issue if a
"book" name is mistyped.

Best regards,

Keary Suska
Esoteritech, Inc.
"Demystifying technology for your home or business"

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message CSN 2005-10-09 19:46:51 Duplicate primary keys/rows
Previous Message David Fetter 2005-10-09 17:01:15 Re: INSERT OR UPDATE?