On Thu, 23 Oct 2003 yusuf0478@netscape.net wrote:
> I'm interested in finding the minimim A.id such that the following holds:
>
> select A.charge
> , B.user_id
> , C.employee_id
> from A
> inner join B using (user_id)
> inner join C using (employee_id)
>
> except
>
> select X.charge
> , Y.user_id
> , Z.employee_id
> from X
> inner join Y using (user_id)
> inner join Z using (employee_id)
>
> --
>
> I can't do the following, since the number of selected columns have to match:
>
> select A.id
> , A.charge
> , B.user_id
> , C.employee_id
> from A
> inner join B using (user_id)
> inner join C using (employee_id)
>
> except
>
> select X.charge
> , Y.user_id
> , Z.employee_id
> from X
> inner join Y using (user_id)
> inner join Z using (employee_id)
Maybe you can add a dummy field in the second half like this:
except
select -1 , X.charge , Y.user_id , Z.employee_id
???