Filling NULL values with Preceding Non-NULL values - Option 2

Filling NULL values with Preceding Non-NULL values - Option 2.sql

-- First of all I'll just put the data from my main table into a temp table 
-- just to make sure i am not destroying the actual data if something went wrong. 
SELECT * INTO #Temp FROM ImportedSales; 
;With CTE As 
( 
SELECT ProductName , Id , COUNT(ProductName) 
OVER(ORDER BY Id ROWS UNBOUNDED PRECEDING) As MyGroup FROM #Temp ), GetProduct AS ( 
                 SELECT [ProductName] , First_Value(ProductName)  
                  OVER(PARTITION BY MyGroup 
                       ORDER BY Id ROWS UNBOUNDED PRECEDING
                       ) As UpdatedProductName FROM CTE 
            ) 
UPDATE GetProduct 
SET ProductName = UpdatedProductName; 
SELECT * FROM #Temp;