Re: Select .. Having vs computer fields

At 12:54 PM 12/12/2001 -0500, Francisco Reyes wrote:
>Can use use computed fields on the "having" part of select?
>I have tried:
>select a,b, count(*) as dups_count from some_table having dups_count > 1;
>
>and it gives me the error "Attribute 'dups_count' not found"

You have to GROUP BY in order to use HAVING. For example:

SELECT a,b, count(*) as dups_count FROM some_table GROUP BY a,b HAVING
dups_count > 1;

You should GROUP your rows by all the columns that are not count() or other
aggregate function (like max(), min(), sum(), etc).

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Javier Dussaillant G.
ashkar(at)vrweb(dot)cl
Departamento de Desarrollo VRWEB ltda.
http://www.vrweb.cl