Date: Thu, 28 Jun 2007 08:28:26 +0200
From: "A. Kretschmer" <andreas.kretschmer@schollglas.com>
To: pgsql-performance@postgresql.org
Subject: Re: update query taking too long
Message-ID: <20070628062826.GC22066@a-kretschmer.de>
References: <46834124.5010600@gmail.com> <21072.1183009270@sss.pgh.pa.us>
	<46835252.5070901@gmail.com>
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am  Thu, dem 28.06.2007, um 16:16:50 +1000 mailte Chris folgendes:
> Is there a better way to write the update? I thought about something 
> like this (but couldn't get it working - guess I don't have the right 
> syntax):
> 
> update t1 set domainname=(select id, SUBSTRING(emailaddress FROM 
> POSITION('@' IN emailaddress)) from table t2) AS t2 where t1.id=t2.id

test=# select * from foo;
 id |    mail     | domain
----+-------------+--------
  1 | foo@foo.tld |
  2 | bar@bar.tld |
(2 rows)

test=*# update foo set domain=SUBSTRING(mail FROM (POSITION('@' IN
mail)+1));
UPDATE 2
test=*# select * from foo;
 id |    mail     | domain
----+-------------+---------
  1 | foo@foo.tld | foo.tld
  2 | bar@bar.tld | bar.tld
(2 rows)


(without the @ in the domain...)


Andreas
-- 
Andreas Kretschmer
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