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Count on a subquery

Jehan Jaleel
Ranch Hand

Joined: Apr 30, 2002
Posts: 196
Hi all,
Is it possible in SQL to do a count on a subquery? For example..

select parent_name , count (select child_id from child a where = from parent p group by parent_name

I know that SQL is wrong. It is meant only to be psuedo-code, but I hope you get the idea.

Thanks for any help.
Campbell Ritchie

Joined: Oct 13, 2005
Posts: 41593
Not sure, but I think yes.
Jan Cumps

Joined: Dec 20, 2006
Posts: 2532

Can you try

select p.parent_name , (select count (a.child_id) from child a where = from parent p

attention: untested.

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Jeanne Boyarsky
author & internet detective

Joined: May 26, 2003
Posts: 31668

This works in postgresql. Not sure if it would work in all databases, but it is fast to try in yours.

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It is sorta covered in the JavaRanch Style Guide.
subject: Count on a subquery