Re: pesky select query

"Ingram, Bryan" <BIngram(at)sixtyfootspider(dot)com> writes:
> What I'd like to do is produce a query that will
> list each app_code and the count of distinct states for that app_code on one
> line. I don't care what the state_code is, I just need to know the number
> of distinct state_codes per app_code.

> So far I've tried variations of select distincts with counts() and group
> by's on various fields. I briefly considered trying to do this with an
> outer join, but I'm not sure it'd work. I'm still using 6.5.x so I'd have to
> simulate it with a union all/subquery. For that reason I thought'd I'd ask
> here first to see if there is a better way.

Update to 7.0.* and do
select app_code, count(distinct state_code) from tab group by app_code;

regards, tom lane