oracle 两个时间相减默认的是天数

oracle 两个时间相减默认的是天数*24 为相差的小时数

oracle 两个时间相减默认的是天数*24*60 为相差的分钟数

oracle 两个时间相减默认的是天数*24*60*60 为相差的秒数

测试如下:

SQL>select sysdate from dual;

       2008-2-20 14:32:35

SQL> select (sysdate-to_date('2008-02-17 23:00:00','yyyy-mm-dd hh24:mi:ss')) from dual;
 
(SYSDATE-TO_DATE('2008-02-1723
------------------------------
              2.64659722222222
 
SQL> select (sysdate-to_date('2008-02-17 23:00:00','yyyy-mm-dd hh24:mi:ss'))*24 from dual;
 
(SYSDATE-TO_DATE('2008-02-1723
------------------------------
                         63.52
SQL> select (sysdate-to_date('2008-02-17 23:00:00','yyyy-mm-dd hh24:mi:ss'))*24*60 from dual;
 
(SYSDATE-TO_DATE('2008-02-1723
------------------------------
                        3811.5
 
SQL> select (sysdate-to_date('2008-02-17 23:00:00','yyyy-mm-dd hh24:mi:ss'))*24*60*60 from dual;
 
(SYSDATE-TO_DATE('2008-02-1723
------------------------------
                        228700