[Err] 1349 - View's SELECT conta

报错语句：

create view q1
as 
select m.user_id,m.dates,n.`首次使用时间`
from 
(select user_id,dates
from a group by user_id,dates) m
inner join 
(select user_id ,min(dates) as `首次使用时间`
from a group by user_id) n 
on m.user_id=n.user_id
order by m.user_id,m.dates;

原因:
mysql视图不支持子查询。那么只能把一个视图拆解成多个