Re: SQL question.

I need to remember to keep things simple...

Works fine, thanks.

Fred

On Jun 1, 2005, at 5:20 PM, Jim Buttafuoco wrote:

> how about (untested)
>
> select *
> from
> (
> SELECT DISTINCT ON (linkid) *
> FROM all_links
> WHERE uid='2' AND DATE_TRUNC('day',read_date) = DATE_TRUNC
> ('day',TIMESTAMP '2005-06-01')
> ORDER BY linkid
> ) A
> ORDER BY read_date DESC limit 100
>
>
> ---------- Original Message -----------
> From: FC <lne-1mc8(at)myamail(dot)com>
> To: pgsql-general(at)postgresql(dot)org
> Sent: Wed, 1 Jun 2005 16:40:48 +0200
> Subject: [GENERAL] SQL question.
>
>
>> Hello SQL Aces !
>>
>> I want to do a select on a table distinct on linkid and sorted by
>> date. I have try this
>>
>> SELECT DISTINCT ON (linkid) * FROM all_links
>> WHERE uid='2' AND DATE_TRUNC('day',read_date) = DATE_TRUNC('day',
>> TIMESTAMP '2005-06-01') ORDER BY linkid, read_date;
>>
>> With this request "works" but the raws are sorted as I want. To have
>> the rows sorted by date I have done this using a temporary table and
>> that works exactly as I want.
>>
>> CREATE LOCAL TEMP TABLE temp_links WITHOUT OIDS AS
>> SELECT DISTINCT ON (linkid) * FROM all_links
>> WHERE uid='2' AND DATE_TRUNC('day',read_date) = DATE_TRUNC('day',
>> TIMESTAMP '2005-06-01') ORDER BY linkid;
>>
>> SELECT * from temp_links ORDER BY read_date DESC limit 100
>>
>> My question is... How can I do the same thing in the more efficient
>> way and without using a temporary table. Since I am using PHP and the
>> table is not deleted at the end of the program because PHP keeps the
>> connection to the database open.
>>
>> Thanks for any suggestions.
>> Fred
>>
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> ------- End of Original Message -------
>
>
>