oracle日期相減獲取時分秒

毫秒

select ceil((To_date('2008-05-02 00:00:00' , 'yyyy-mm-dd hh24-mi-ss')-To_date('2008-04-30 23:59:59' , 'yyyy-mm-dd hh24-mi-ss')) *24*60*60) FROM DUAL

秒

select ceil((To_date('2008-05-02 00:00:00' , 'yyyy-mm-dd hh24-mi-ss')-To_date('2008-04-30 23:59:59' , 'yyyy-mm-dd hh24-mi-ss')) *24*60) FROM DUAL

小時

select ceil((To_date('2008-05-02 00:00:00' , 'yyyy-mm-dd hh24-mi-ss')-To_date('2008-04-30 23:59:59' , 'yyyy-mm-dd hh24-mi-ss')) *24) FROM DUAL

天

select ceil(To_date('2008-05-02 00:00:00' , 'yyyy-mm-dd hh24-mi-ss')-To_date('2008-04-30 23:59:59' , 'yyyy-mm-dd hh24-mi-ss')) FROM DUAL