From: Richard Huxton <dev@archonet.com>
To: Gary Stainburn <gary.stainburn@ringways.co.uk>
To: pgsql-sql@postgresql.org
Subject: Re: master-detail relationship and count
Date: Fri, 29 Nov 2002 10:35:12 +0000
Message-ID: <200211291035.12923.dev@archonet.com> (raw)
In-Reply-To: <200211291006.06749.gary.stainburn@ringways.co.uk>
References: <200211291006.06749.gary.stainburn@ringways.co.uk>
On Friday 29 Nov 2002 10:06 am, Gary Stainburn wrote:
> Hi folks.
>
> I've got a master detail relationship where I have a railway route table
> listing landmarks along the route, and a Links table listing URL's
> associated with that landmark. Listed below:
>
> How can I do a query showing the landmark ID, the landmark name, and a
> count of links associated with that landmark. Below is a SQL statement
> that although is illegal, gives a good idea of what I'm looking for.
>
> select r.rtid, r.rtname, l.count(*) from route r, links l where l.lktype =
> 'R' and l.lklid = r.rtid;
You'll want to GROUP BY
SELECT r.rtid, r.rtname, l.count(*) FROM route r, links l WHERE l.lktype='R'
AND l.lklid=r.rtid GROUP BY r.rtid, r.rtname;
--
Richard Huxton
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To: pgsql-sql@postgresql.org
Cc: dev@archonet.com, gary.stainburn@ringways.co.uk
Subject: Re: master-detail relationship and count
In-Reply-To: <200211291035.12923.dev@archonet.com>
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