Received: from lists.unixathome.org (lists.unixathome.org [210.48.103.158])
	by postgresql.org (Postfix) with ESMTP id 6B2CC4759BD
	for <pgsql-sql@postgresql.org>; Sat,  2 Mar 2002 17:35:34 -0500 (EST)
Received: from wocker (lists.unixathome.org [210.48.103.158])
	by lists.unixathome.org (8.11.6/8.11.6) with ESMTP id g22MZYk55756
	for <pgsql-sql@postgresql.org>; Sun, 3 Mar 2002 11:35:34 +1300 (NZDT)
	(envelope-from dan@lists.unixathome.org)
Message-Id: <200203022235.g22MZYk55756@lists.unixathome.org>
From: "Dan Langille" <dan@langille.org>
Organization: DVL Software Limited
To: pgsql-sql@postgresql.org
Date: Sat, 2 Mar 2002 17:35:31 -0500
MIME-Version: 1.0
Subject: using LIMIT only on primary table
Reply-To: dan@langille.org
X-mailer: Pegasus Mail for Windows (v4.01)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
X-Archive-Number: 200203/19
X-Sequence-Number: 6901

If I want the last 100 orders:

SELECT * FROM orders LIMIT 100;

If I want all the items on the last 100 orders, I'd start like this:

SELECT * 
from orders, order_items 
where order_items.order_id = orders.id
LIMIT 100

But that will only give me the last 100 items, not 100 orders.

What I really want is 

SELECT * 
from orders, order_items 
where order_items.order_id = orders.id
and exists
(SELECT * from orders order by ID DESC limit 100);

But that gives me all orders, not just the first 100.

Adding a LIMIT 100 to the above doesn't work either.  It equates to the 
first example.

Clues?  cheers
-- 
Dan Langille
The FreeBSD Diary - http://freebsddiary.org/ - practical examples