From: Joel Richard <postgres@joelrichard.com>
To: D'Arcy J.M. Cain <darcy@druid.net>
To: Claudia Kosny <ckosny@gmx.net>
Cc: sql pgsql <pgsql-sql@postgresql.org>
Subject: Re: fetch first rows of grouped data
Date: Mon, 27 Aug 2007 13:34:09 -0400
Message-ID: <4CB5D209-C0CC-466E-A967-E766D6AD799B@joelrichard.com> (raw)
In-Reply-To: <20070827125102.e52b43de.darcy@druid.net>
References: <46D2FD9F.3020000@gmx.net>
<20070827125102.e52b43de.darcy@druid.net>
That's what I thought at first, but this is not the case. She's
looking for the first two dates in -each- city in the table. I
initially thought that this could be accomplished with GROUP BY and
LIMIT, but GROUP BY can only give you the first date for each city,
not the first two dates for each city.
So far, I haven't come up with any clever ideas. I'm not sure this
can be done in SQL.
--Joel
On Aug 27, 2007, at 12:51 PM, D'Arcy J.M. Cain wrote:
> On Mon, 27 Aug 2007 18:36:47 +0200
> Claudia Kosny <ckosny@gmx.net> wrote:
>> I have a list of events that take place in a certain city at a
>> certain
>> date. Now I would like to have the first two (ordered by date) events
>> for each city.
>>
>> Is there a way to do this with one query?
>> I am using PostgreSQL 7.4.
>
> I believe you are looking for the LIMIT keyword. Check the docs on
> the
> web site.
>
> --
> D'Arcy J.M. Cain <darcy@druid.net> | Democracy is three
> wolves
> http://www.druid.net/darcy/ | and a sheep voting on
> +1 416 425 1212 (DoD#0082) (eNTP) | what's for dinner.
>
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Subject: Re: fetch first rows of grouped data
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