| From: | Jean-Luc Lachance <jllachan(at)nsd(dot)ca> |
|---|---|
| To: | josh(at)agliodbs(dot)com |
| Cc: | Marco Muratori <marco(dot)muratori(at)emaze(dot)net>, pgsql-sql(at)postgresql(dot)org |
| Subject: | Re: query problem |
| Date: | 2002-08-30 20:02:53 |
| Message-ID: | 3D6FCF6D.8E072AE0@nsd.ca |
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| Thread: | |
| Lists: | pgsql-sql |
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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