google sheets - Sum of every row where two conditions are met

Question

I have two spreadsheets. The first is a list of products, the second is a list of sales.

The products spreadsheet includes four columns: "SKU", "Shipment ID", "Quantity Purchased", and "Remaining Quantity."

     A           B                   C                        D
     SKU      Shipment ID   Qty Purchased   Remaining Qty
1   20121   X2992            40                      38
2   20121   X8483            40                      40
3   71662   X2242            40                      39

The sales spreadsheet includes three columns: "SKU", "Shipment ID", and "Quantity Sold."

     A           B                   C
     SKU      Shipment ID   Qty Sold
1   20121   X2992            1
2   71662   X2242            1
3   20121   X2992            1

I want "Remaining Quantity" to be calculated. Each row of this column should take the "Quantity Purchased" from it's own row and subtract the "Quantity Sold" from the sales spreadsheet for every row where the "SKU" and "Shipment ID" match the "SKU" and "Shipment ID" from its own row. What is the formula for this? (Many formulas are the same in Excel, so I'm tagging Excel as well.)

Answer 1

Try this formula in the products sheet cell D2 copied down

=C2-ArrayFormula(SUM(IF(Sales!A$2:A$100=A2,IF(Sales!B$2:B$100=B2,Sales!C$2:C$100))))

That assumes data up to row 100 in Sales sheet, adjust as required