STR_TO_DATE(str,format) 这是DATE_FORMAT()函数的反函数。它需要一个字符串str和一个格式字符串格式。STR_TO_DATE()返回一个DATETIME值。

开发要求，获取当月佣金，主要卡在了sql对datetime 类型的判断

先后用过4种方法如下

1.select sum('price') from rrr_order_level where active_time < "2015-09-30 00:00:00";

2.select sum('price') from rrr_order_level where timestampdiff(hour,'2008-08-08 12:00:00','2008-08-08 00:00:00') > 0

3.select sum('price') from rrr_order_level where active_time < '$EndDate' and active_time > '$BeginDate'"

4.select sum('price') from rrr_order_level where active_time between '2015-09-01 00:00:00' and '2015-09-30 00:00:00';

数据库如上

分析错误，mysql不知道对应的年月日，无法比较，采用

select sum(price) from rrr_order_level where active_time >= STR_TO_DATE('2015-09-01 00:00:00','%Y-%m-%d %H:%i:%s') and active_time <= STR_TO_DATE('2015-09-30 00:00:00','%Y-%m-%d %H:%i:%s');

完美解决问题！