What is the difference in order number from "WARE-MKL1006" and "WARE-NBV1002"?
"WARE-NBV1002" and "WARE-MKL1006" are both WarehouseCode; difference in order number = Subtract(Count(OrderNumber where WarehouseCode = 'WARE-MKL1006'), Count(OrderNumber where WarehouseCode = 'WARE-NBV1002'))
SELECT SUM(IIF(WarehouseCode = 'WARE-MKL1006', 1, 0)) - SUM(IIF(WarehouseCode = 'WARE-NBV1002', 1, 0)) AS difference FROM `Sales Orders`