On Fri, Apr 15, 2005 at 21:58:31 +1000,
Alex <alex@xxxxxxxxxxxxxxx> wrote:
> Hi,
>
> i have a table
>
> ProdId | LastUpdate
> -------+------------
> 100 | 2005-04-01
> 100 | 2005-03-01
> 100 | 2005-02-01
> 200 | 2005-04-01
> 200 | 2005-03-01
> 200 | 2005-02-01
>
> - How can i select only the newest record for each ProdId ?
>
> 100 | 2005-04-01
> 200 | 2005-04-01
You can also use the Postgres specific DISTINCT ON clause.
SELECT DISTINCT ON (prodid) prodid, lastupdate ORDER BY prodid, lastupdate DESC;
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
