SQL SERVER Update query : I need SQL SERVER Update query without using Cursor or while looping on table to Update projected stock . when  projectedStock < ReorderPoint add OrderQuantity
for Example :
ReorderPoint	1600
OrderQuantity	1200

    Date	ProjectedStock 
    15/03/2017	125
    16/03/2017	-172
    17/03/2017	-172
    18/03/2017	-796
    19/03/2017	-796
    20/03/2017	-1420
    21/03/2017	-1717
needed Results :

    Date	ProjectedStock
    15/03/2017	1325
    16/03/2017	2228
    17/03/2017	2228
    18/03/2017	1604
    19/03/2017	1604
    20/03/2017	2180
    21/03/2017	1883

Thanks .
