Re: SELECT query

On Wed, 14 Mar 2001, G. Anthony Reina wrote:

> I think it would be something like:
> select distinct subject, arm, rep from circles_proc where rep = (select
> rep  from circles_proc where 5 = count(cycle));

You're heading towards

SELECT distinct subject, arm, rep FROM circles_proc WHERE rep IN
  (SELECT rep FROM circles_proc GROUP BY rep HAVING COUNT(rep)=5);

A possible variant would be

SELECT distinct subject, arm, rep FROM circles_proc c1 WHERE EXISTS
  (SELECT rep FROM circles_proc c2 WHERE c1.rep=c2.rep GROUP BY reg HAVING
   COUNT(rep)=5)

though w/a small set of test data, this seems less efficient.

There's also

SELECT DISTINCT subj, arm, rep FROM circles_proc c1 WHERE 5=
  (SELECT COUNT(rep) FROM circles_proc c2 where c1.rep=c2.rep);

but, again, EXPLAIN thinks this will be less efficient.


Unless you get a great solution elsewhere :-), try indexing the fields
and testing the different queries above.

Good luck,

--
Joel Burton   <jburton@scw.org>
Director of Information Systems, Support Center of Washington