Re: Looking for the correct solution for a generic problem.

Frank Joerdens <frank@joerdens.de> writes:
> This works fine if there is *at least* one row in B for each row in A.
> If there isn't, I obviously get 0 results even if the column foo in A
> matches the desired criteria. But I do want the rows from A even if
> there is no row in B that is linked to those rows in A that match the
> criteria.

You want an "outer join".  Something likeFROM A LEFT JOIN B ON (A.id = B.a_id)WHERE [other criteria]
        regards, tom lane