From: Greg Stark <gsstark@mit.edu>
To: Josh Berkus <josh@agliodbs.com>
Cc: Stefan Bill <sjb26@yahoo.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: LEAST and GREATEST functions?
Date: 01 Jul 2003 12:29:16 -0400
Message-ID: <87d6gu2otf.fsf@stark.dyndns.tv> (raw)
In-Reply-To: <200306302032.23113.josh@agliodbs.com>
References: <20030630201057.14507.qmail@web13905.mail.yahoo.com>
<200306302032.23113.josh@agliodbs.com>
Josh Berkus <josh@agliodbs.com> writes:
> Stefan,
>
> > I know the LEAST and GREATEST functions are not part
> > of standard SQL, but they sure were handy where I came
> > from (Oracle-land).
>
> Um, what's wrong with MAX and MIN, exactly?
MAX and MIN are single-parameter aggregate functions. LEAST and GREATEST are
two-parameter (though in postgres they could be defined for 3 and more
parameters) scalar functions.
eg:
SELECT max(a) FROM bar
would return a single tuple with the maximum value of a from amongst every
record. whereas:
SELECT greatest(a,b) FROM bar
would return one tuple for every record in the table with a single value
representing the greater of bar.a and bar.b.
You could define your own functions to do this but it would be tiresome to
define one for every datatype.
--
greg
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To: pgsql-sql@postgresql.org
Cc: gsstark@mit.edu, josh@agliodbs.com, sjb26@yahoo.com
Subject: Re: LEAST and GREATEST functions?
In-Reply-To: <87d6gu2otf.fsf@stark.dyndns.tv>
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