Mysql——日期函数，时间操作（汇总）

英文文档连接：https://dev.mysql.com/doc/refman/5.6/en/date-and-time-functions.html

mysql 获取当天0点 和 当天23点59分59秒

SELECT DATE_FORMAT('2019-08-08','%Y-%m-%d %H:%i:%s');

SELECT DATE_SUB( DATE_ADD('2019-08-08', INTERVAL 1 DAY),INTERVAL 1 SECOND)

  以下翻译至官方文档：

• ADDDATE(date,INTERVAL expr unit)， ADDDATE(expr,days) 将指定的时间间隔值加到时间上

mysql> SELECT DATE_ADD('2008-01-02', INTERVAL 31 DAY);
        -> '2008-02-02'
mysql> SELECT ADDDATE('2008-01-02', INTERVAL 31 DAY);
        -> '2008-02-02'

        如果不指定时间间隔单位时，默认为单位为天

mysql> SELECT ADDDATE('2008-01-02', 31);
        -> '2008-02-02'

•  ADDTIME(expr1,expr2)　将时间表达式expr2加到expr1上

mysql> SELECT ADDTIME('2007-12-31 23:59:59.999999', '1 1:1:1.000002');
        -> '2008-01-02 01:01:01.000001'
mysql> SELECT ADDTIME('01:00:00.999999', '02:00:00.999998');
        -> '03:00:01.999997'

• CURDATE() 以‘YYYY-MM-DD’形式或值的形式返回当前时间

mysql> SELECT CURDATE();   -- 默认返回的形式是'YYYY-MM-DD'
        -> '2008-06-13'
mysql> SELECT CURDATE() + 0; -- +0返回的数值
        -> 20080613

• DATE(expr)  获取指定时间的年月日部分

mysql> SELECT DATE('2003-12-31 01:02:03');
        -> '2003-12-31'

• DATEDIFF(expr1,expr2) 返回时间值expr1 - 时间值expr2之间相差的天数。

mysql> SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30');
        -> 1
mysql> SELECT DATEDIFF('2010-11-30 23:59:59','2010-12-31');
        -> -31

• DATE_ADD(date,INTERVAL expr unit)  时间添加，将指定的时间间隔expr添加至date上，返回值取决于date的格式
• DATE_SUB(date,INTERVAL expr unit)  时间相减，将指定的时间间隔expr添加至date上，返回值取决于date的格式 

mysql> SELECT DATE_ADD('2018-05-01',INTERVAL 1 DAY);
        -> '2018-05-02'
mysql> SELECT DATE_SUB('2018-05-01',INTERVAL 1 YEAR);
        -> '2017-05-01'
mysql> SELECT DATE_ADD('2020-12-31 23:59:59',INTERVAL 1 SECOND);
        -> '2021-01-01 00:00:00'
mysql> SELECT DATE_ADD('2018-12-31 23:59:59', INTERVAL 1 DAY);
        -> '2019-01-01 23:59:59'
mysql> SELECT DATE_ADD('2100-12-31 23:59:59',INTERVAL '1:1' MINUTE_SECOND);
        -> '2101-01-01 00:01:00'
mysql> SELECT DATE_SUB('2025-01-01 00:00:00', INTERVAL '1 1:1:1' DAY_SECOND);
        -> '2024-12-30 22:58:59'
mysql> SELECT DATE_ADD('1900-01-01 00:00:00', INTERVAL '-1 10' DAY_HOUR);
        -> '1899-12-30 14:00:00'
mysql> SELECT DATE_SUB('1998-01-02', INTERVAL 31 DAY);
        -> '1997-12-02'
mysql> SELECT DATE_ADD('1992-12-31 23:59:59.000002',INTERVAL '1.999999' SECOND_MICROSECOND);
        -> '1993-01-01 00:00:01.000001'

• DATE_FORMAT(date,format) date根据format的格式转换成字符串

mysql> SELECT DATE_FORMAT('2009-10-04 22:23:00', '%W %M %Y');
        -> 'Sunday October 2009'
mysql> SELECT DATE_FORMAT('2007-10-04 22:23:00', '%H:%i:%s');
        -> '22:23:00'
mysql> SELECT DATE_FORMAT('1900-10-04 22:23:00',
    ->                 '%D %y %a %d %m %b %j');
        -> '4th 00 Thu 04 10 Oct 277'
mysql> SELECT DATE_FORMAT('1997-10-04 22:23:00',
    ->                 '%H %k %I %r %T %S %w');
        -> '22 22 10 10:23:00 PM 22:23:00 00 6'
mysql> SELECT DATE_FORMAT('1999-01-01', '%X %V');
        -> '1998 52'
mysql> SELECT DATE_FORMAT('2006-06-00', '%d');
        -> '00'
mysql> SELECT DATE_FORMAT('1997-10-04 22:23:00', '%Y%m%d%H%i%s');
        -> '19971004222300'

• DAYNAME(date) 返回指定日期是周几

mysql> SELECT DAYNAME('2007-02-03');
        -> 'Saturday'

• DAYOFMONTH(date) 返回指定日期是这个月的第几天，返回数值

mysql> SELECT DAYOFMONTH('2007-02-03');
        -> 3

• DAYOFWEEK(date) 返回指定日期的周几（1=周日，2=星期一，…，7=周六）

mysql> SELECT DAYOFWEEK('2007-02-03');
        -> 7

• DAYOFYEAR(date) 返回一年中的第几天（1-366）

mysql> SELECT DAYOFYEAR('2007-02-03');
        -> 34

• FROM_DAYS(N) 给定天数N，返回DATE值

mysql> SELECT FROM_DAYS(730669);
        -> '2000-07-03'

• FROM_UNIXTIME(unix_timestamp[,format]) 将时间戳转换成‘YYYY-MM-DD hh:mm:ss’格式或者指定格式

mysql> SELECT FROM_UNIXTIME(1447430881);
        -> '2015-11-13 10:08:01'
mysql> SELECT FROM_UNIXTIME(1447430881) + 0;
        -> 20151113100801
mysql> SELECT FROM_UNIXTIME(1447430881,'%Y %D %M %h:%i:%s %x');
        -> '2015 13th November 10:08:01 2015'

• LAST_DAY(date) 返回当月最后一天的相应值

mysql> SELECT LAST_DAY('2003-02-05');
        -> '2003-02-28'
mysql> SELECT LAST_DAY('2004-02-05');
        -> '2004-02-29'
mysql> SELECT LAST_DAY('2004-01-01 01:01:01');
        -> '2004-01-31'
mysql> SELECT LAST_DAY('2003-03-32');
        -> NULL

• NOW([fsp]) 返回当前日期'YYYY-MM-DD hh:mm:ss'或作为值的YYYYMMDDhhmmss 


mysql> SELECT NOW();
        -> '2007-12-15 23:50:26'
mysql> SELECT NOW() + 0;
        -> 20071215235026.000000

• PERIOD_ADD(P,N) 将N个月添加到时间P中（其中P只能是‘YYMM’或‘YYYYMM’）格式，返回格式为‘YYYYMM’

mysql> SELECT PERIOD_ADD(200801,2);
        -> 200803

• SYSDATE([fsp]) 获取当前执行时间，与now()不一样，now()的时间是恒定的，而sysdate（）是执行该函数的时间

mysql> SELECT NOW(), SLEEP(2), NOW();
+---------------------+----------+---------------------+
| NOW()               | SLEEP(2) | NOW()               |
+---------------------+----------+---------------------+
| 2006-04-12 13:47:36 |        0 | 2006-04-12 13:47:36 |
+---------------------+----------+---------------------+

mysql> SELECT SYSDATE(), SLEEP(2), SYSDATE();
+---------------------+----------+---------------------+
| SYSDATE()           | SLEEP(2) | SYSDATE()           |
+---------------------+----------+---------------------+
| 2006-04-12 13:47:44 |        0 | 2006-04-12 13:47:46 |
+---------------------+----------+---------------------+

• UNIX_TIMESTAMP([date]) 如果不带参数，则返回一个unix时间戳；如果带date格式，则返回与'1970-01-01 00:00:00'UTC 相差的秒数形式的参数值 

mysql> SELECT UNIX_TIMESTAMP();
        -> 1447431666
mysql> SELECT UNIX_TIMESTAMP('2015-11-13 10:20:19');
        -> 1447431619
mysql> SELECT UNIX_TIMESTAMP('2015-11-13 10:20:19.012');
        -> 1447431619.012

• CONVERT_TZ(dt,from_tz,to_tz)　将dt的时间值从from_tz的时区转换至to_tz的时区

mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET');
        -> '2004-01-01 13:00:00'
mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','+00:00','+10:00');
        -> '2004-01-01 22:00:00'