From: Gary Stainburn <gary.stainburn@ringways.co.uk>
To: pgsql-sql@postgresql.org
Subject: Re: foreign key question
Date: Wed, 5 Jan 2011 10:40:08 +0000
Message-ID: <201101051040.08575.gary.stainburn@ringways.co.uk> (raw)
In-Reply-To: <201101050953.43830.gary.stainburn@ringways.co.uk>
References: <201101050953.43830.gary.stainburn@ringways.co.uk>
On Wednesday 05 January 2011 09:53:43 Gary Stainburn wrote:
> Now I want to set up a new access level table specific to the itinerary,
> along the lines of
>
> u_id int4 not null references users(u_id)
> fl_level int4 not null references facility_levels(16, fl_level)
>
> Firstly, is this possible, and secondly how would I do it?
I've managed a work-around by creating a column that defaults to 16 and then
used ALTER TABLE ADD CONSTRAINT to add a foreign key with two pairs of keys.
This feels wrong though as my table now has a column that is ultimately
redundant, and worse can be changed to a wrong value.
Ok, I've sorted the last bit by adding a check constraint to make sure it
always contains 16, but it still feels wrong.
--
Gary Stainburn
I.T. Manager
Ringways Garages
http://www.ringways.co.uk
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To: pgsql-sql@postgresql.org
Cc: gary.stainburn@ringways.co.uk
Subject: Re: foreign key question
In-Reply-To: <201101051040.08575.gary.stainburn@ringways.co.uk>
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