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Linux系统运维与架构

作者:丁原 | 【转载时请务必以超链接形式标明文章原始出处和作者信息及本声明】
地址:http://rdc.taobao.com/blog/dba/html/234_mysql_date_func.html

通常我们会有一些时间的转换需求,比如要统计某个时间段的收入,比如要截取某个时间的年份,比如要根据某个日期推算出是星期几等个,这些都可以通过Mysql自带的时间函数很容易实现。因为我对Mysql的函数还不熟,而通常又会调用这些时间函数,这边稍加总结以便查询。
–返回当前时间

mysql> select now(),date(now()),sysdate();
+---------------------+-------------+---------------------+
| now()               | date(now()) | sysdate()           |
+---------------------+-------------+---------------------+
| 2008-12-02 10:11:36 | 2008-12-02  | 2008-12-02 10:11:36 |
+---------------------+-------------+---------------------+
1 row in set (0.00 sec)
mysql> select curdate(),curdate()+0,curtime(),curtime()+0;       
+---------------------+-------------+---------------------+
| curdate()  | curdate()+0 | curtime() | curtime()+0   |
+---------------------+-------------+---------------------+
| 2008-12-02 | 20081202    | 10:00:33  | 100033.000000 |
+---------------------+-------------+---------------------+

–返回日期当月最后一天

mysql> select last_day('2008-12-02');
+------------------------+
| last_day('2008-12-02') |
+------------------------+
| 2008-12-31             |
+------------------------+
1 row in set (0.00 sec)

–返回日期的星期几

mysql> select dayname('2008-12-02'),dayofweek('2008-12-02');
+-----------------------+-------------------------+
| dayname('2008-12-02') | dayofweek('2008-12-02') |
+-----------------------+-------------------------+
| tuesday               |                       3 |
+-----------------------+-------------------------+
1 row in set (0.00 sec)

–返回日期的年,月,日

mysql> select month('2008-12-02'),year('2008-12-02'),day('2008-12-02');
+---------------------+--------------------+-------------------+
| month('2008-12-02') | year('2008-12-02') | day('2008-12-02') |
+---------------------+--------------------+-------------------+
|                  12 |               2008 |                 2 |
+---------------------+--------------------+-------------------+
1 row in set (0.00 sec)

–返回日期的小时,分,秒

mysql> select hour('10:05:03'),minute('10:05:03'),second('10:05:03');       
+------------------+--------------------+--------------------+
| hour('10:05:03') | minute('10:05:03') | second('10:05:03') |
+------------------+--------------------+--------------------+
|               10 |                  5 |                  3 |
+------------------+--------------------+--------------------+
1 row in set (0.00 sec)

1.subdate(d,t):起始时间加上一段时间(year,month,day…)

mysql> select date_add('1998-01-02', interval 31 day),adddate('1998-01-02', 31);      
+-----------------------------------------+---------------------------+
| date_add('1998-01-02', interval 31 day) | adddate('1998-01-02', 31) |
+-----------------------------------------+---------------------------+
| 1998-02-02                              | 1998-02-02                |
+-----------------------------------------+---------------------------+
1 row in set (0.00 sec)
mysql> select date_add('1998-01-02',interval 2 year);
+-----------------------------------------------------+
| date_add('1998-01-02', interval 2 year) 
+-----------------------------------------------------+
| 2000-01-02                                 
+-----------------------------------------------------+
1 row in set (0.00 sec)
mysql> select date_add('1998-01-02', interval 2 hour);
+-----------------------------------------------------+
| date_add('1998-01-02', interval 2 hour) 
+-----------------------------------------------------+
| 1998-01-02 02:00:00                    
+-----------------------------------------------------+
1 row in set (0.00 sec)

2.subdate(d,t):起始时间减去一段时间

mysql> select subdate('1998-01-02', interval 31 day),subdate('1998-01-02', 31);
+----------------------------------------+---------------------------+
| subdate('1998-01-02', interval 31 day) | subdate('1998-01-02', 31) |
+----------------------------------------+---------------------------+
| 1997-12-02                             | 1997-12-02                |
+----------------------------------------+---------------------------+
1 row in set (0.00 sec)

3.addtime(d,t):起始时间d加入时间t

mysql> select addtime('1997-12-31 23:59:50','00:00:05'), addtime('23:59:50','00:00:05') ;
+-------------------------------------------+--------------------------------+
| addtime('1997-12-31 23:59:50','00:00:05') | addtime('23:59:50','00:00:05') |
+-------------------------------------------+--------------------------------+
| 1997-12-31 23:59:55                       | 23:59:55                       |
+-------------------------------------------+--------------------------------+
1 row in set (0.00 sec)

4.subtime(d,t):起始时间d减去时间t

mysql> select subtime('1997-12-31 23:59:50','00:00:05'), subtime('23:59:50','00:00:05');     
+-------------------------------------------+--------------------------------+
| subtime('1997-12-31 23:59:50','00:00:05') | subtime('23:59:50','00:00:05') |
+-------------------------------------------+--------------------------------+
| 1997-12-31 23:59:45                       | 23:59:45                       |
+-------------------------------------------+--------------------------------+
1 row in set (0.00 sec)

5.datediff(d1,d2):返回起始时间d1和结束时间d2之间的天数

mysql> select datediff('1997-12-31 23:59:59','1997-12-30');
+----------------------------------------------+
| datediff('1997-12-31 23:59:59','1997-12-30') |
+----------------------------------------------+
|                                            1 |
+----------------------------------------------+
1 row in set (0.00 sec)

6.date_format(date,format):根据format字符串显示date值的格式

mysql> select date_format('2008-12-02 22:23:00', '%y %m %m %h:%i:%s');
+---------------------------------------------------------+
| date_format('2008-12-02 22:23:00', '%y %m %m %h:%i:%s') |
+---------------------------------------------------------+
| 2008 12 12 22:23:00                                     |
+---------------------------------------------------------+
1 row in set (0.00 sec)

7.str_to_date(str,format) 字符串转化为时间

mysql> select str_to_date('04/31/2004', '%m/%d/%y %h:%i:s');
+-----------------------------------------------+
| str_to_date('04/31/2004', '%m/%d/%y %h:%i:s') |
+-----------------------------------------------+
| 2004-04-31 00:00:00                           |
+-----------------------------------------------+
1 row in set (0.00 sec)

8.timestamp(expr) , timestamp(expr,expr2) :
对于一个单参数,该函数将日期或日期时间表达式 expr 作为日期时间值返回.对于两个参数, 它将时间表达式 expr2添加到日期或日期时间表达式 expr 中,将theresult作为日期时间值返回

mysql> select timestamp('2003-12-31'), timestamp('2003-12-31 12:00:00','12:00:00');
+-------------------------+---------------------------------------------+
| timestamp('2003-12-31') | timestamp('2003-12-31 12:00:00','12:00:00') |
+-------------------------+---------------------------------------------+
| 2003-12-31 00:00:00     | 2004-01-01 00:00:00                         |
+-------------------------+---------------------------------------------+
1 row in set (0.00 sec)

9.取当天0点0分,下一天0点0分

mysql> select timestamp(date(sysdate())),timestamp(adddate(date(sysdate()),1));      
+----------------------------+---------------------------------------+
| timestamp(date(sysdate())) | timestamp(adddate(date(sysdate()),1)) |
+----------------------------+---------------------------------------+
| 2008-12-02 00:00:00        | 2008-12-03 00:00:00                   |
+----------------------------+---------------------------------------+
1 row in set (0.00 sec)

转载请注明出处:http://dp2u.com/2008/mysql-time-func.html

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