DELETE
FROM 
    ORDERS
WHERE EXISTS(
    SELECT 1
    FROM 
        ORDERS_DTL
    WHERE
        ORDERS.ORDER_NO = ORDERS_DTL.ORDER_NO
);

-- DELETE 
-- FROM
--     ORDERS 
-- USING INNER JOIN
--     ORDERS_DTL 
-- ON
--     ORDERS.ORDER_NO = ORDERS_DLT.ORDER_NO
-- WHERE
--     ORDERS.ORDER_DATE BETWEEN '2010-01-01 00:00:00' AND '2010-12-31 23:59:59';