效果:
数据库:
============
建表,插入数据
============
CREATE TABLE `test` (
`id` int(4) NOT NULL auto_increment,
`name` varchar(20) default NULL,
`createtime` datetime default NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
insert into `test`(`id`,`name`,`createtime`) values (1,'1','2009-01-01 12:12:12'),(2,'2','2009-01-02 12:12:12'),(3,'2','2009-02-01 12:12:12'),(4,'2','2009-02-02 12:12:12'),(5,'2','2009-03-01 12:12:12'),(6,'2','2009-03-02 12:12:12'),(7,'2','2009-04-02 12:12:12');
效果:
=======
查询语句
=======
select count(id) '总数', DATE_FORMAT(createtime,'%Y-%m') as '月份'
from test group by DATE_FORMAT(createtime,'%Y-%m')
效果
注: DATE_FORMAT(date,format) 参照: http://www.w3school.com.cn/sql/func_date_format.asp