SQL Update to the SUM of its joined values

Question

I\'m trying to update a field in the database to the sum of its joined values:

UPDATE P
SET extrasPrice = SUM(E.price)
FROM dbo.BookingPitchExtras AS E
INNER         


        

Answer 1

I ran into the same issue and found that I could solve it with a Common Table Expression (available in SQL 2005 or later):

;with cte as (
    SELECT PitchID, SUM(Price) somePrice
    FROM BookingPitchExtras
    WHERE [required] = 1 
    GROUP BY PitchID)
UPDATE p SET p.extrasPrice=cte.SomePrice
FROM BookingPitches p INNER JOIN cte ON p.ID=cte.PitchID
WHERE p.BookingID=1