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DELETE FROM t WHERE EXISTS

From: "Dan Langille" <dan(at)langille(dot)org>
To: pgsql-sql(at)postgresql(dot)org
Subject: DELETE FROM t WHERE EXISTS
Date: 2003-02-28 17:16:11
Message-ID: 3E5F530B.1649.424D34C1@localhost (view raw or flat)
Thread:
Lists: pgsql-sql
Hi folks,

I wanted to delete "old" rows from a table.  These are the rows I 
want to keep:

SELECT * 
FROM clp 
ORDER BY commit_date 
LIMIT 100

So I tried this:

DELETE FROM clp 
WHERE NOT EXISTS (
SELECT * 
FROM clp 
ORDER BY commit_date 
LIMIT 100);

Uhh uhh, nothing deleted.  I don't understand why.

OK, I can do this instead:

DELETE from clp 
where commit_log_id NOT in (
SELECT commit_log_id 
FROM clp 
ORDER BY commit_date 
LIMIT 100);

Can you think of a better way?
-- 
Dan Langille : http://www.langille.org/


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Subject: Re: WebDB, iAS
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