该函数获取两个日期的差值，并以日期格式yyyy-mm-dd显示。您只需要执行下面的代码，然后使用该函数。执行后，您可以像这样使用它

SELECT datedifference(date1, date2)
FROM ....
.
.
.
.


DELIMITER $$

CREATE FUNCTION datedifference(date1 DATE, date2 DATE) RETURNS DATE
NO SQL

BEGIN
    DECLARE dif DATE;
    IF DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(date1), '-', DAY(date2)))) < 0    THEN
                SET dif=DATE_FORMAT(
                                        CONCAT(
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))DIV 12 , 
                                            '-',
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))% 12 , 
                                            '-',
                                            DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(DATE_SUB(date1, INTERVAL 1 MONTH)), '-', DAY(date2))))),
                                        '%Y-%m-%d');
    ELSEIF DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(date1), '-', DAY(date2)))) < DAY(LAST_DAY(DATE_SUB(date1, INTERVAL 1 MONTH))) THEN
                SET dif=DATE_FORMAT(
                                        CONCAT(
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))DIV 12 , 
                                            '-',
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))% 12 , 
                                            '-',
                                            DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(date1), '-', DAY(date2))))),
                                        '%Y-%m-%d');
    ELSE
                SET dif=DATE_FORMAT(
                                        CONCAT(
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))DIV 12 , 
                                            '-',
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))% 12 , 
                                            '-',
                                            DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(date1), '-', DAY(date2))))),
                                        '%Y-%m-%d');
    END IF;

RETURN dif;
END $$
DELIMITER;

该函数获取两个日期的差值，并以日期格式yyyy-mm-dd显示。您只需要执行下面的代码，然后使用该函数。执行后，您可以像这样使用它

SELECT datedifference(date1, date2)
FROM ....
.
.
.
.


DELIMITER $$

CREATE FUNCTION datedifference(date1 DATE, date2 DATE) RETURNS DATE
NO SQL

BEGIN
    DECLARE dif DATE;
    IF DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(date1), '-', DAY(date2)))) < 0    THEN
                SET dif=DATE_FORMAT(
                                        CONCAT(
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))DIV 12 , 
                                            '-',
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))% 12 , 
                                            '-',
                                            DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(DATE_SUB(date1, INTERVAL 1 MONTH)), '-', DAY(date2))))),
                                        '%Y-%m-%d');
    ELSEIF DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(date1), '-', DAY(date2)))) < DAY(LAST_DAY(DATE_SUB(date1, INTERVAL 1 MONTH))) THEN
                SET dif=DATE_FORMAT(
                                        CONCAT(
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))DIV 12 , 
                                            '-',
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))% 12 , 
                                            '-',
                                            DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(date1), '-', DAY(date2))))),
                                        '%Y-%m-%d');
    ELSE
                SET dif=DATE_FORMAT(
                                        CONCAT(
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))DIV 12 , 
                                            '-',
                                            PERIOD_DIFF(date_format(date1, '%y%m'),date_format(date2, '%y%m'))% 12 , 
                                            '-',
                                            DATEDIFF(date1, DATE(CONCAT(YEAR(date1),'-', MONTH(date1), '-', DAY(date2))))),
                                        '%Y-%m-%d');
    END IF;

RETURN dif;
END $$
DELIMITER;

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

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。

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?