DELETE
FROM
 ORDERS_DTL 
WHERE
 ORDER_NO IN
 (SELECT O.ORDER_NO FROM ORDERS O INNER JOIN ORDERS_DTL D ON O.ORDER_NO = D.ORDER_NO WHERE O.ORDER_DATE BETWEEN '2010-01-01' AND '2010-12-31')
;

DELETE FROM ORDERS
WHERE ORDER_DATE BETWEEN '2010-01-01' AND '2010-12-31'
;