Using AdventureWorks2016CTP3 Modify the following query to execute its check code only if the Quantity column is updated:

CREATE TRIGGER tgrExcessInventory

on Production.ProductInventory

FOR UPDATE

AS

IF EXISTS

(SELECT 'True'

FROM Inserted i

JOIN Deleted d

ON i.productID = d.ProductID

AND i.locationID = d.LocationID

WHERE (d.quantity + i.quantity) >= 1000 OR

i.quantity >=1000

)

BEGIN

RAISERROR('Cannot increase stock where units would be over 1,000 units',16,1)

ROLLBACK TRAN

END