From: Joost Kraaijeveld <J.Kraaijeveld@Askesis.nl>
To: pgsql-sql@postgresql.org
Subject: Can I do this smarter?
Date: Fri, 14 Jul 2006 05:41:28 +0200
Message-ID: <1152848488.6045.13.camel@localhost> (raw)
I have three tables: customers, salesorders and invoices. Customers have
salesorders and salesorders have invoices ( child tables have foreign
key columns to their parent).
I want to get a list of all invoices with their customers. This what I
came up with:
select
invoices.objectid,
invoices.invoicenumber,
invoices.invoicedate,
(select customer from salesorders where objectid = invoices.salesorderobjectid),
(select customernumber from customers where objectid = (select customer from salesorders where objectid = invoices.salesorderobjectid)),
(select lastname from customers where objectid = (select customer from salesorders where objectid = invoices.salesorderobjectid))
from invoices
Can I do this smarter as the three subselects select the same customer three times and I would think that 1 time is enough?
TIA
--
Groeten,
Joost Kraaijeveld
Askesis B.V.
Molukkenstraat 14
6524NB Nijmegen
tel: 024-3888063 / 06-51855277
fax: 024-3608416
web: www.askesis.nl
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To: pgsql-sql@postgresql.org
Cc: J.Kraaijeveld@Askesis.nl
Subject: Re: Can I do this smarter?
In-Reply-To: <1152848488.6045.13.camel@localhost>
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