On Tue, Aug 7, 2012 at 5:07 PM, Stefan Keller <sfkeller@gmail.com> wrote:
> Hi Craig
>
> Clever proposal!
> I slightly tried to adapt it to the hstore involved.
> Now I'm having a weird problem that PG says that "relation 'p' does not exist".
> Why does PG recognize table b in the subquery but not table p?
> Any ideas?
I don't think it does recognize b, either. It just fell over on p
before it had a chance to fall over on b.
I think you have to use WITH if you want to reference the same
subquery in multiple FROMs.
Another approach would be to add explicit conditions for there being
at least 1 school and 1 pharmacy within distance. There can't be >1
unless there is >=1, but the join possibilities for >=1 (i.e. "where
exists" rather than "where (select count(*)...)>1" ) are much more
attractive than the ones for >1.
Cheers,
Jeff