If you do not have foreign key restrinctions, create a temp table from
the select as:
CREATE TEMP TABLE tmp AS SELECT DISTINCT ON (location) location, time,
report FROM weatherReports ORDER BY location, time DESC;
TRUNCATE weatherReports; INSERT INTO weatherReports SELECT * FROM tmp;
HTH
Achilleus Mantzios wrote:
> O kyrios Christoph Haller egrapse stis Jun 16, 2004 :
>
>
>>Referring to the DISTINCT ON example
>>
>>SELECT DISTINCT ON (location) location, time, report
>>FROM weatherReports
>>ORDER BY location, time DESC;
>
>
> maybe smth like
>
> delete from weatherReports where (location,time,report) not in
> (SELECT DISTINCT ON (location) location, time, report FROM weatherReports
> ORDER BY location, time DESC)
>
> Note:
> Order by is very important, since it affects which rows are deleted.
>
>
>>How would I delete those entries skipped by the DISTINCT ON expression?
>>
>>TIA
>>
>>Regards, Christoph
>>
>>
>>
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>
>
