Oh... and also, A, B, C are in the same table. 2009/4/17 Shug Boabby <shug.boabby@xxxxxxxxx>: > Life sure would be easier if that were the case Michal, but no... that > is not the case here. The sum is not a simple sum, it is a sum of all > elements having a lower or equal A and the same C. This is a > "cumulative sum" as pointed out by others. > > 2009/4/15 Michal Politowski <mpol+pg@xxxxxxx>: >> 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; > -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
