CASE
WHEN ORDER_MODE = 'online' then ORDER_TOTAL = SUM(ORDER_TOTAL*0.20)
WHEN ORDER_STATUS = '1'THEN ORDER_TOTAL = SUM(ORDER_TOTAL*0.10)

A CASE expression to return ORDER_TOTAL + 20% when the ORDER_MODE is ‘online’ and ORDER_TOTAL + 10% when the ORDER_STATUS is 1.