From: Jean-Luc Lachance <jllachan@nsd.ca>
To: josh@agliodbs.com
Cc: Marco Muratori <marco.muratori@emaze.net>
Cc: pgsql-sql@postgresql.org
Subject: Re: query problem
Date: Fri, 30 Aug 2002 16:02:53 -0400
Message-ID: <3D6FCF6D.8E072AE0@nsd.ca> (raw)
References: <Pine.LNX.4.30.0208301824330.25859-100000@marco.intranet>
<200208291345.25680.josh@agliodbs.com>
I think you meant min(date)...
Josh Berkus wrote:
>
> Marco,
>
> > Is there a way to obtain this records by performing one
> > single query and not by making for each city something like
> > "SELECT city,date FROM table WHERE city='London' AND date>'2002-07-19
> > 15:39:15+00' ORDER BY date ASC LIMIT 1;"?
>
> Close. Try:
>
> SELECT city, MAX("date") as last_date
> FROM table
> WHERE "date" > $date
> GROUP BY city
> ORDER BY city
>
> Though as an aggregate query, this will be slow on large tables.
>
> --
> -Josh Berkus
> Aglio Database Solutions
> San Francisco
>
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To: pgsql-sql@postgresql.org
Cc: jllachan@nsd.ca, josh@agliodbs.com, marco.muratori@emaze.net
Subject: Re: query problem
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