Calcular WAM y WAIR es bastante simple. Piense sumproduct() en Excel
Declare @YourTable table (SaleEventID int,LID int,CurrentUPB money,[Interest Rate] money,RemainingMonths money)
Insert Into @YourTable values
(1,1,100000.00,6.100, 11.00),
(1,2,67000.00,6.200, 360.00),
(1,3,1400000.00,6.300, 240.00),
(1,4,500000.00,7.000, 100.00),
(2,5,1400000.00,7.100, 240.00),
(2,6,500000.00,7.000,100.00)
Select SaleEventID
,UPB = sum(CurrentUPB)
,WAM = sum(CurrentUPB*RemainingMonths)/sum(CurrentUPB)
,WAIR = sum(CurrentUPB*[Interest Rate] )/sum(CurrentUPB)
From @YourTable
Where SaleEventID = @Event
Group By SaleEventID
Devoluciones
SaleEventID UPB WAM WAIR
1 2067000.00 198.9453 6.4564
2 1900000.00 203.1578 7.0736