你可以简单地这样做:

SELECT (end_time - start_time) FROM t; -- return in Millisecond
SELECT (end_time - start_time)/1000 FROM t; -- return in Second

使用DATEDIFF获取日期差异(以天为单位)

SELECT DATEDIFF('2010-10-08 18:23:13', '2010-09-21 21:40:36') AS days;
+------+
| days |
+------+
|   17 |
+------+

OR

参考下面的链接 MySql的两个时间戳在天之间的差异?

SELECT TIMESTAMPDIFF(HOUR,NOW(),'2013-05-15 10:23:23')
   calculates difference in hour.(for days--> you have to define day replacing hour
SELECT DATEDIFF('2012-2-2','2012-2-1')

SELECT TO_DAYS ('2012-2-2')-TO_DAYS('2012-2-1')

select TO_CHAR(TRUNC(SYSDATE)+(to_date( '31-MAY-2012 12:25', 'DD-MON-YYYY HH24:MI') 
                             - to_date( '31-MAY-2012 10:37', 'DD-MON-YYYY HH24:MI')), 
        'HH24:MI:SS') from dual

——结果:01:48:00

好吧，这不是OP要求的，但这是我想做的:-)

select 
unix_timestamp('2007-12-30 00:00:00') - 
unix_timestamp('2007-11-30 00:00:00');

SELECT TIMESTAMPDIFF(SECOND,'2018-01-19 14:17:15','2018-01-20 14:17:15');

第二种方法

选择(DATEDIFF(1993-02-20)、1993-02-19)

CURRENT_TIME() --this will return current Date
DATEDIFF('','') --this function will return  DAYS and in 1 day there are 24hh 60mm 60sec