Sum based on two conditions

[jfelker88]

Hello - I am trying to create a Sum expression based on two conditions - If Field A is distinct, and Field B is the same, sum the quantity. The example data set: 

Matching	Matching1	Quantity
12345	68038986	-310.000
12345	68038986	-
12345	68038986	-
56789	68038986	-310.000
56789	68038986	-
56789	68038986	-
34567	68038986	-310.000
34567	68038986	-
34567	68038986	-
98765	68038986	-310.000
98765	68038986	-
98765	68038986	-
10293	68038986	310.000
10293	68038986	-
10293	68038986	-
28374	68038986	310.000
28374	68038986	-
28374	68038986	-
74563	68038986	310.000
74563	68038986	-
74563	68038986	-
57893	68038986	310.000
57893	68038986	-
57893	68038986	-

In this case,  take distinct Matching value and Matching1 = Matching1, then sum the quantity. Using these conditions you would get a net zero quantity with this example. 

I have the first part figured out, but not sure how to add the second condition where Matching1 is the same: 

sum(aggr(sum(DISTINCT [Quantity]), [Matching]))

Any help is appreciated. 

[jochem_zw]

Please try:

sum(aggr(sum(DISTINCT [Quantity]), [Matching],[Matching1]))