On Wed, 15 Apr 2009 15:32:42 +0100, Shug Boabby wrote:
> I simplified my problem a little too much and now I'm stuck trying to
> use cumulative_sum(). My schema is not only A, B but also has a C
>
> A B C
> 1 0 1
> 2 1 1
> 3 0 1
> 4 2 1
> 5 1 1
> 1 0 2
> 2 1 2
> 3 0 2
> 4 2 2
> 5 1 2
>
> and I want to be able to do the cumulative sum only when C is the same. E.g.
>
> A funkySumB C
> 1 0 1
> 2 1 1
> 3 1 1
> 4 3 1
> 5 4 1
> 1 0 2
> 2 1 2
> 3 1 2
> 4 3 2
> 5 4 2
If I understand the problem correctly, why not just something like this?:
SELECT t1.a, sum(t2.b), t1.c FROM abc t1 JOIN abc t2 ON t2.a <= t1.a AND
t2.c=t1.c GROUP BY t1.a, t1.c;
--
Michał Politowski
Talking has been known to lead to communication if practiced carelessly.