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

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

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

为什么不干脆

从表中选择Sum(Date1 - Date2)

Date1和date2是datetime

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')

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