delete from ORDERS_DTL 
where  exists (
  select * from ORDERS ord 
  where ord.ORDER_NO = ORDERS_DTL.ORDER_NO
  and   ord.ORDER_DATE between '2010-01-01' and '2010-12-31'
);

delete from ORDERS
where ORDER_DATE between '2010-01-01' and '2010-12-31'
;