为什么不干脆

从表中选择Sum(Date1 - Date2)

Date1和date2是datetime

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'

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 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');

如果你在文本字段中存储了一个日期作为字符串，你可以实现这段代码，它将获取过去一周，一个月或一年排序的天数列表:

SELECT * FROM `table` WHERE STR_TO_DATE(mydate, '%d/%m/%Y') < CURDATE() - INTERVAL 30 DAY AND STR_TO_DATE(date, '%d/%m/%Y') > CURDATE() - INTERVAL 60 DAY

//This is for a month

SELECT * FROM `table` WHERE STR_TO_DATE(mydate, '%d/%m/%Y') < CURDATE() - INTERVAL 7 DAY AND STR_TO_DATE(date, '%d/%m/%Y') > CURDATE() - INTERVAL 14 DAY

//This is for a week 

%d%m%Y是日期格式

This query display the record between the days you set there like: Below from last 7 days and Above from last 14 days so it would be your last week record to be display same concept is for month or year. Whatever value you're providing in below date like: below from 7-days so the other value would be its double as 14 days. What we are saying here get all records above from last 14 days and below from last 7 days. This is a week record you can change value to 30-60 days for a month and also for a year.

希望它能帮助到别人。