where附近语法异常

where附近语法错误？
select course_number ,count(*) as cnt,sum(online_time) as totaltime from stu_study group by course_number where stu_number='20110012' 
我的语句如上。
表中字段:
stu_number(学号)
course_number(课程号)
online_time(int,在线时长)

学生有重复值，课程也有重复值，现在想找某一个学生的不同课程的情况.
sqlserver提示:

消息 156，级别 15，状态 1，第 1 行
关键字 'where' 附近有语法错误。


[解决办法]

SQL code

select course_number ,count(*) as cnt,sum(online_time) as totaltimefrom stu_study where stu_number='20110012'  group by course_number
[解决办法]
把where 写着group by 前面
[解决办法]
select course_number ,count(*) as cnt,sum(online_time) as totaltime from stu_study
where stu_number='20110012'  
  group by course_number  
where必须在group by前面