Content-Type: text/plain;
  charset="iso-8859-1"
From: Gary Stainburn <gary.stainburn@ringways.co.uk>
Organization: Ringways Garages Ltd
To: PostgreSQL-sql <pgsql-sql@postgresql.org>
Subject: Re: sub-sel/group problem
Date: Mon, 11 Aug 2003 11:38:43 +0100
User-Agent: KMail/1.4.3
References: <200308111124.07832.gary.stainburn@ringways.co.uk>
In-Reply-To: <200308111124.07832.gary.stainburn@ringways.co.uk>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Message-Id: <200308111138.43196.gary.stainburn@ringways.co.uk>

On Monday 11 August 2003 11:24 am, Gary Stainburn wrote:
> Hi folks,
>
> I don;t know if it's cos it's Monday or what, but I can't see what's wrong
> here.
>
> I've got two tables, turns which holds a turn number, a task, and where
> appropriate a link to a loco.  The select below works but only shows those
> tasks where a loco is involved.:
>
[snip]

Having re-read my email and had another go, I've opted for the sub-select 
approach, and come up with:

select rtid, concat(task) from 
    (select  rtid, 
     case when r.rlid > 0 then
       r.rcid::text || ' on ' || l.lnumber::text
     else
       r.rcid::text
     end as task
    from rides r
     left outer join loco_dets l on r.rlid = l.lid) r
    group by rtid
    order by rtid
;

Can anyone see any problems with this, or come up with a better approach?
-- 
Gary Stainburn
 
This email does not contain private or confidential material as it
may be snooped on by interested government parties for unknown
and undisclosed purposes - Regulation of Investigatory Powers Act, 2000