Re: where clause subqueries vs multiple rows results

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От Aaron Bono
Тема Re: where clause subqueries vs multiple rows results
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Msg-id bf05e51c0609102155i1683e18fg47ed27b77113d153@mail.gmail.com
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Ответ на Re: where clause subqueries vs multiple rows results  ("Aaron Bono" <postgresql@aranya.com>)
Список pgsql-sql
Oops, see correction below...

On 9/10/06, Aaron Bono <postgresql@aranya.com> wrote:
On 9/10/06, James Cloos <cloos@jhcloos.com> wrote:
I've a query which I'd have liked to word akin to:

  SELECT guid FROM child WHERE the_fkey =
         ( SELECT id FROM parent WHERE name ~ 'some_regex' )
         ORDER BY the_fkey, my_pkey;

I got around it by doing the SELECT id first, and then doing a SELECT
guid for each row returned, appending the results together.

Can that be done in a single query, insead of 1+n queries?

 
Will this work?

SELECT guid
FROM child
INNER JOIN parent ON (
    child.the_fkey = parent.id
)
WHERE name ~ 'some_regex'
ORDER BY
    child.the_fkey,
    child.my_pkey
;

I am not sure what table name is from but since you say it is n+1 queries I assume it is from the child table?  It would help to know what columns are on which tables.

==================================================================
   Aaron Bono
   Aranya Software Technologies, Inc.
   http://www.aranya.com
   http://codeelixir.com
==================================================================



--
==================================================================
   Aaron Bono
   Aranya Software Technologies, Inc.
   http://www.aranya.com
   http://codeelixir.com
==================================================================

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