DELETE FROM ORDERS
WHERE ORDERS.ORDER_DATE BETWEEN '2010-1-1' AND '2010-12-31';

DELETE FROM ORDERS_DTL
WHERE ORDER_NO IN(SELECT ORDERS.ORDER_NO FROM ORDERS INNER JOIN ORDERS_DTL ON ORDERS.ORDER_NO = ORDERS_DTL.ORDER_NO
WHERE ORDERS.ORDER_DATE BETWEEN '2010-1-1' AND '2010-12-31');