Date: Sun, 03 Mar 2002 15:00:01 +0900
From: Masaru Sugawara <rk73@sea.plala.or.jp>
To: dan@langille.org
Subject: Re: using LIMIT only on primary table
Cc: pgsql-sql@postgresql.org
In-Reply-To: <200203022235.g22MZYk55756@lists.unixathome.org>
References: <200203022235.g22MZYk55756@lists.unixathome.org>
Errors-To: rk73@sea.plala.or.jp
Message-Id: <20020303141057.614C.RK73@sea.plala.or.jp>
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On Sat, 2 Mar 2002 17:35:31 -0500
"Dan Langille" <dan@langille.org> wrote:

> 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);


This probably gives you all the items on the last 100 orders.

 select * 
  from (select * from orders order by ID desc limit 10) as o
       inner join order_items as oi
        on (oi.order_id = o.order_id)
;


> 
> 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.


Regards,
Masaru Sugawara