DELETE FROM ORDERS_DTL
WHERE ORDER_NO IN 
 (SELECT ORDER_NO FROM ORDERS as T1 
  WHERE T1.ORDER_DATE >= '2010-01-01'
   AND T1.ORDER_DATE <= '2010-12-31');

DELETE 
FROM 
 ORDERS
WHERE ORDERS.ORDER_DATE >= '2010-01-01'
 AND ORDERS.ORDER_DATE <= '2010-12-31';