Date: Fri, 15 Feb 2002 15:51:07 -0600
From: GB Clark <postgres@vsservices.com>
To: pgsql-sql@postgresql.org
Message-Id: <20020215155107.1e405665.postgres@vsservices.com>
In-Reply-To: <20020215104908.Y37614-100000@megazone23.bigpanda.com>
References: <002101c1b650$18f087a0$0201a8c0@osprey>
	<20020215104908.Y37614-100000@megazone23.bigpanda.com>
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Hi,

Can anyone give me a couple of examples or a explanation of select for update is supposed to work?

I've looked in the manual and the locking stuff is confusing (or it could just be me not understanding..))
 and neither of my SQL books go into any type of detail on locking.

What I want to do is select a record, do something and then update that record to reflect the outcome
of the processing with 0% chance of another process doing the same thing.  Is this possiable?

my idea:

BEGIN
SELECT * FROM table1 WHERE record_id = '290202' FOR UPDATE
-- Do processing here
UPDATE table1 SET flag1 = '11' WHERE record_id = '290202'
COMMIT

Just looking for more information....

Thanks,

GB

-- 
GB Clark II             | Roaming FreeBSD Admin
gclarkii@VSServices.COM | General Geek 
           CTHULU for President - Why choose the lesser of two evils?