题解 | #分组计算练习题#

select 
gender,
university,
count(id) as user_num,//2.利用对应函数进行计算就行，下面以此类推
avg(active_days_within_30) as avg_active_day,
avg(question_cnt) as avg_question_cnt
from user_profile 
group by gender,university //1.进行正确的分组，可以先观察分组后的数据是否符合要求