X-Original-To: pgsql-sql-postgresql.org@postgresql.org
Received: from localhost (mx1.hub.org [200.46.208.251])
	by postgresql.org (Postfix) with ESMTP id A645B9FB1C0
	for <pgsql-sql-postgresql.org@postgresql.org>;
	Thu,  6 Jul 2006 04:00:27 -0300 (ADT)
Received: from postgresql.org ([200.46.204.71])
	by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024)
	with ESMTP id 32764-04 for <pgsql-sql-postgresql.org@postgresql.org>;
	Thu,  6 Jul 2006 04:00:19 -0300 (ADT)
X-Greylist: domain auto-whitelisted by SQLgrey-
Received: from ug-out-1314.google.com (ug-out-1314.google.com [66.249.92.168])
	by postgresql.org (Postfix) with ESMTP id 1AADB9FA603
	for <pgsql-sql@postgresql.org>; Thu,  6 Jul 2006 04:00:18 -0300 (ADT)
Received: by ug-out-1314.google.com with SMTP id a2so2559976ugf
	for <pgsql-sql@postgresql.org>; Thu, 06 Jul 2006 00:00:17 -0700 (PDT)
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com;
	h=received:message-id:date:from:reply-to:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references;
	b=abzQ5Kvm2ys7TpaZZEdNFBmy//7orLLbfs2ACnKaOMO0XbzlkHhbvGjoTNxxRdcL/wQYtspWb+SJJRqYxoC6+Bqjolkw6okD/Og8EcsWi50Mz3kFRs4208vIMsuoWMdCVohF85/9wIj2XJ7QPjRSnSRZir/Wd7g0ayi8nfV4IxY=
Received: by 10.67.26.7 with SMTP id d7mr326741ugj;
	Thu, 06 Jul 2006 00:00:17 -0700 (PDT)
Received: by 10.67.24.20 with HTTP; Thu, 6 Jul 2006 00:00:17 -0700 (PDT)
Message-ID: <a55915760607060000w6b1ce1b8rc5a2eb3aec2ad31e@mail.gmail.com>
Date: Thu, 6 Jul 2006 02:00:17 -0500
From: "Rodrigo De Leon" <rdeleonp@gmail.com>
Reply-To: rdeleonp@gmail.com, rdeleonp@yahoo.com
To: pgsql-sql@postgresql.org
Subject: Re: week ending
In-Reply-To: <44AC8F6A.4090704@NarrowPathInc.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
References: <44AC8F6A.4090704@NarrowPathInc.com>
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Archive-Number: 200607/52
X-Sequence-Number: 25626

On 7/5/06, Keith Worthington <KeithW@narrowpathinc.com> wrote:
> Hi All,
>
> I just finished writing a query that groups data based on the week number.
>
> SELECT EXTRACT(week FROM col_a) AS week_number,
>         sum(col_b) AS col_b_total
>    FROM foo
>   WHERE foobar
>   GROUP BY EXTRACT(week FROM col_a)
>   ORDER BY EXTRACT(week FROM col_a);
>
> I would like to generate the starting date or ending date based on this
> number.  IOW instead of telling the user "week number" which they won't
> understand I would like to provide either Friday's date for "week
> ending" or Monday's date for "week beginning".
>
> SELECT <something> AS week_ending,
>         sum(col_b) AS col_b_total
>    FROM foo
>   WHERE foobar
>   GROUP BY EXTRACT(week FROM col_a)
>   ORDER BY EXTRACT(week FROM col_a);
>
> --
>
> Kind Regards,
> Keith

select
max(case when (to_char(col_a,'d') between 2 and 6) then col_a end) as
week_ending,
sum(col_b) as col_b_total from foo
where foobar
group by extract(year from col_a), extract(week from col_a)
order by extract(year from col_a), extract(week from col_a);

Regards,

Rodrigo