mysql date_add date_sub
mysql中内置函数date_add和date_sub能对指定的时间进行增加或减少一个指定的时间间隔,语法如下: DATE_ADD(date,INTERVAL expr type)DATE_SUB(date,INTERVAL expr type) 其中date是指定的日期,INTERVAL为关键词,expr是具体的时间间隔,type是时间单位。注
mysql中内置函数date_add和date_sub能对指定的时间进行增加或减少一个指定的时间间隔,语法如下:
DATE_ADD(date,INTERVAL expr type) DATE_SUB(date,INTERVAL expr type)
其中date是指定的日期,INTERVAL为关键词,expr是具体的时间间隔,type是时间单位。注意:type可以复合型的,比如YEAR_MONTH。如果type不是复合型的,DATE_ADD和DATE_SUB其实可以通用,因为expr可以为一个负数。可用的type如下表:
MICROSECOND | 间隔单位:毫秒 |
SECOND | 间隔单位:秒 |
MINUTE | 间隔单位:分钟 |
HOUR | 间隔单位:小时 |
DAY | 间隔单位:天 |
WEEK | 间隔单位:星期 |
MONTH | 间隔单位:月 |
QUARTER | 间隔单位:季度 |
YEAR | 间隔单位:年 |
SECOND_MICROSECOND | 复合型,间隔单位:秒、毫秒,expr可以用两个值来分别指定秒和毫秒 |
MINUTE_MICROSECOND | 复合型,间隔单位:分、毫秒 |
MINUTE_SECOND | 复合型,间隔单位:分、秒 |
HOUR_MICROSECOND | 复合型,间隔单位:小时、毫秒 |
HOUR_SECOND | 复合型,间隔单位:小时、秒 |
HOUR_MINUTE | 复合型,间隔单位:小时分 |
DAY_MICROSECOND | 复合型,间隔单位:天、毫秒 |
DAY_SECOND | 复合型,间隔单位:天、秒 |
DAY_MINUTE | 复合型,间隔单位:天、分 |
DAY_HOUR | 复合型,间隔单位:天、小时 |
YEAR_MONTH | 复合型,间隔单位:年、月 |
对应复合型的type,需要使用引号对两个参数进行引用起来,中间用任何非数字字符作为间隔即可,并且不能使用负数。但是时间间隔只指定了一个值,那么也能正常工作,但是对应XXX_YYY使用的单位为YYY,也就相当于单一单位的type,同时可以使用负数。复合型的用法如下:
mysql> select date_add('2013-01-18', interval '1 2' YEAR_MONTH); +-----------------------------------------------------+ | date_add('2013-01-18', interval '1 2' YEAR_MONTH) | +-----------------------------------------------------+ | 2014-03-18 | +-----------------------------------------------------+ mysql> select date_add('2013-01-18', interval '1-2' YEAR_MONTH); +----------------------------------------------------+ | date_add('2013-01-18', interval '1-2' YEAR_MONTH) | +----------------------------------------------------+ | 2014-03-18 | +----------------------------------------------------+ mysql> select date_add('2013-01-18', interval '1,2' YEAR_MONTH); +---------------------------------------------------+ | date_add('2013-01-18', interval '1,2' YEAR_MONTH) | +---------------------------------------------------+ | 2014-03-18 | +---------------------------------------------------+ mysql> select date_add('2013-01-18', interval 1 YEAR_MONTH); +-----------------------------------------------+ | date_add('2013-01-18', interval 1 YEAR_MONTH) | +-----------------------------------------------+ | 2013-02-18 | +-----------------------------------------------+ mysql> select date_add('2013-01-18', interval -1 YEAR_MONTH); +------------------------------------------------+ | date_add('2013-01-18', interval -1 YEAR_MONTH) | +------------------------------------------------+ | 2012-12-18 | +------------------------------------------------+
原文地址:mysql date_add date_sub, 感谢原作者分享。

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