Thank you. I understand it somewhat more now. There are 2 more parts that confuse me.

What is the relationship between SET @strSellerNo2 = NULL and IF (@strSellerNo2 IS NULL).

Also how does Seller_No <> @strSellerNo1 when it seems that it was fetched as Seller_No=SellerNo1. I commented out the parts that confused me.

DECLARE @strProductNo varchar(20)

--DECLARE @strSellerNo1 varchar(10)

DECLARE @strSellerNo2 varchar(10)

DECLARE UpdateProductCursor CURSOR FOR

--SELECT Product_No, Seller_No

FROM Outlet.tblProductMaster

WHERE Product_Status IS NULL

OPEN UpdateProductCursor

--FETCH NEXT FROM UpdateProductCursor INTO @strProduct_No, @strSellerNo1

WHILE @@FETCH_STATUS = 0

BEGIN

SET @strSellerNo2 = NULL

SELECT @strSellerNo2 = Seller_No

FROM Outlet.tblProductMaster

WHERE Product_No = @strProductNo

--AND Seller_No <> @strSellerNo1

AND Product_Status = 'Available'