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

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'

SELECT TIMEDIFF('2007-12-31 10:02:00','2007-12-30 12:01:01');
-- result: 22:00:59, the difference in HH:MM:SS format


SELECT TIMESTAMPDIFF(SECOND,'2007-12-30 12:01:01','2007-12-31 10:02:00'); 
-- result: 79259  the difference in seconds

因此，您可以使用TIMESTAMPDIFF来实现您的目的。

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

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

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')