Hi,

> My original hope was that I would return the results (1, 25.00, 14.00)
> but I instead get (1, 75.00, 28.00). The joins take place between all
> records including the costs/sales tables. Is there any way around this?
> For what I'm doing, I really cannot use any sub select statements, nor
> can I use two separate select statements. Is it possible to do this
> with just one?

For this case it would be possible to use something like:
select m.id, sum(s.sales)/3 salessum, sum(c.costs)/3 costssum
from maintable m
left join salestable s on s.id = m.id
left join coststable c on c.id = m.id
where m.id = 1
group by m.id

I can't think of a better way to do it with a single statement. I guess
the performance would be bad with many records.

Michael