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HomeDatabaseMysql TutorialDetailed explanation of commonly used time functions in MySQL (recommended)

2.6 DATE_SUB/DATE_ADD

DATE_SUB(date,INTERVAL expr type)

date parameter is a legal date expression. The expr parameter is the time interval you wish to add.

SELECT id FROM my_table WHERE create_time >= date_sub(now(), INTERVAL 3 HOUR) AND create_

Type Value

•MICROSECOND
•SECOND
•MINUTE
•HOUR
•DAY
•WEEK
•MONTH
•QUARTER
•YEAR
•SECOND_MICROSECOND
•MINUTE_MICROSECOND
•MINUTE_SECOND
•HOUR_MICROSECOND
•HOUR_SECOND
•HOUR_MINUTE
•DAY_MICROSECOND
•DAY_SECOND
•DAY_MINUTE
•DAY_HOUR
•YEAR_MONTH

2.7 Time addition and subtraction

When we give now()+- a time, it should actually be understood like this:

+1/ +01: Add 1 second
+101/+0101: Add 1 minute 1 second
+10101/+010101: Add 1 hour 1 minute 1 second
+1010101/+01010101: Add 1 day 1 hour 1 minute 1 Seconds
+101010101/+0101010101: Add January, 1 day, 1 hour, 1 minute and 1 second
+1101010101/+010101010101: Add 1 year, January 1 day, 1 hour, 1 minute and 1 second. Please pay attention here, the year is The part can be 4 digits (zeros will be added if the high bit is missing): 00010101010101

2.8 DATE_DIFF/TIME_DIFF

DATEDIFF(date1,date2)

DATEDIFF() function returns the number of days between two dates (only days), date1 and date2 parameters are legal datetime/date expressions.

select datediff('2016-03-29','2016-03-29');
  
select datediff('2016-03-29 00:00:00','2016-03-29 23:59:59');


TIMEDIFF(date1,date2)

TIMEDIFF() function returns the hours, minutes and seconds (HH:MM:ss) between two dates. The date1 and date2 parameters are datetime/time expressions.

select timediff('2016-03-30 00:00:00','2016-03-28 11:11:11');
  
select timediff('00:00:00','11:11:11');


2.9 DATE_FORMAT

DATE_FORMAT(date,format)
DATE_FORMAT() function is used to display date/time data in different formats.

SELECT DATE_FORMAT(insert_time,'%Y-%m-%d %H:%i:%S') AS insert_time FROM user;
  
SELECT DATE_FORMAT(insert_time,'%Y-%m-%d') AS day, COUNT(id) AS count FROM user GROUP BY day;
格式 描述
%a 缩写星期名
%b 缩写月名
%c 月,数值
%D 带有英文前缀的月中的天
%d 月的天,数值(00-31)
%e 月的天,数值(0-31)
%f 微秒
%H 小时 (00-23)
%h 小时 (01-12)
%I 小时 (01-12)
%i 分钟,数值(00-59)
%j 年的天 (001-366)
%k 小时 (0-23)
%l 小时 (1-12)
%M 月名
%m 月,数值(00-12)
%p AM 或 PM
%r 时间,12-小时(hh:mm:ss AM 或 PM)
%S 秒(00-59)
%s 秒(00-59)
%T 时间, 24-小时 (hh:mm:ss)
%U 周 (00-53) 星期日是一周的第一天
%u 周 (00-53) 星期一是一周的第一天
%V 周 (01-53) 星期日是一周的第一天,与 %X 使用
%v 周 (01-53) 星期一是一周的第一天,与 %x 使用
%W 星期名
%w 周的天 (0=星期日, 6=星期六)
%X 年,其中的星期日是周的第一天,4 位,与 %V 使用
%x 年,其中的星期一是周的第一天,4 位,与 %v 使用
%Y 年,4 位
%y 年,2 位

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