题解 | #分组计算练习题#

select
    gender,
    university,
    count(device_id) as user_num,-- 我们统计设备id就可以知道人数了
    avg(active_days_within_30) as avg_active_day,
    avg(question_cnt) as avg_question_cnt
from
    user_profile
group by
    university,
    gender
	 再根据大学,和性别分组