In my opinion, these queries make the same :
SELECT id FROM article WHERE id=(SELECT MAX(id) FROM article);
SELECT MAX(id) FROM article;
but the latter one is much more simple and you do not overload your pg.
(by the way, I think id = (SELECT ...) isn't handled gracefully.)
----- Original Message -----
From: "Jason" <gee308@mediaone.net>
To: <pgsql-php@postgresql.org>
Cc: <pgsql-novice@postgresql.org>; <pgsql-general@postgresql.org>
Sent: 2001. május 3. 14:06
Subject: [PHP] psql with PHP question
> Hi, I want to try and optimize my calls to postgreSQL from PHP. If
> I only need one field from a select statement, what should I use? I am
> currently using:
> $q = pg_Exec("SELECT id FROM article WHERE id=(SELECT MAX(id)
> FROM article)");
> $maxid = pg_fetch_array($q, 0);
> echo "The highest id is ". $maxid[0];
> What can I use besides an array to get a single value? In general, using
> a single variable always saves more memory than using an array? Thank
> you.
> Jason
>
>
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