select ceil((sysdate - To_date('2017-03-23 00:00:00' , 'yyyy-mm-dd hh24-mi-ss')) * 24 * 60 * 60 * 1000) 
相差豪秒數 FROM DUAL;

select ceil((sysdate -TO_DATE( TO_CHAR(a.dcur_state_start_date,'YYYY-MM-DD HH24:MI:SS'),
 'YYYY-MM-DD HH24:MI:SS')) * 24 * 60 * 60 * 1000) 
相差豪秒數 from account a where rownum =1 ;