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

如果您正在使用DATE列(或者可以将它们转换为日期列)，请尝试DATEDIFF()，然后乘以24小时、60分钟、60秒(因为DATEDIFF返回的天数不同)。从MySQL:

http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html

例如:

mysql> SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30 00:00:00') * 24*60*60

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')

或者，您可以使用TIMEDIFF函数

mysql> SELECT TIMEDIFF('2000:01:01 00:00:00', '2000:01:01 00:00:00.000001');
'-00:00:00.000001'
mysql> SELECT TIMEDIFF('2008-12-31 23:59:59.000001' , '2008-12-30 01:01:01.000002');
 '46:58:57.999999'

如果你想添加带有DATEDIFF的where子句，那么也可以添加where子句或条件。 请看下面的例子。

select DATEDIFF(now(), '2022-08-12 17:55:51.000000') from properties p WHERE p.property_name = 'KEY';

结果:6

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