Re: query that needs two nested queries, is this the best

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От Richard Huxton
Тема Re: query that needs two nested queries, is this the best
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Msg-id 4450F8A4.8000802@archonet.com
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Ответ на query that needs two nested queries, is this the best way?  (Mark Harrison <mh@pixar.com>)
Ответы Re: query that needs two nested queries, is this the best  (Mark Harrison <mh@pixar.com>)
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Mark Harrison wrote:
>
> ### QUERY 3:  combine the two statements above by using two subselects
>
> scratch1=# select id from p4_versions where
>            versionof=(select id from p4_files where p4path like
> '%/date.txt')
>            and
>            version=(select headver from p4_files where p4path like
> '%/date.txt');

This won't work if your LIKE matches more than one row anyway.

Try something like:

SELECT id FROM p4_versions WHERE
   (versionof, version) IN (SELECT id,headver FROM p4_files WHERE ...)

--
   Richard Huxton
   Archonet Ltd

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