select university,age,max(count(device_id)) max_cnt
from user_profile
group by university,age
order by max_cnt desc
这个我写的,报错
select age , max(cnt) max_cnt
from
(select age , university , count(*) cnt
from user_profile
group by age , university) t
group by age
order by max_cnt desc
这个答案
我想问,max里面不是不能再套一个count嘛,本想着group by两个字段。