Can someone please look at my code and tell me where I am going wrong. I need to compare 2 tables and need to sum up to columns (temp.quantity) and cart1 (quantityout). Both tables have a common column called barcode. The code works when the temp table does not have duplicate rows of a particular barcode. I thought Sum() and group by barcode would add all the duplicates by barcode. But, it's not working. I also have negative and postive numbers, so I am only trying to add the positive numbers in that column.
select Temp.Barcode,sum(cart1.QuantityOut+Temp.Quantity) AS SumQuantityOut
from Cart1,Temp
where Cart1.Barcode=Temp.Barcode and Temp.Quantity > -1
group by Temp.Barcode
UPDATE Cart1
SET QuantityOut = '#SumQuantityOut#'
WHERE Barcode = '#barcode#'
