题解 | 分组计算练习题

select gender,university,
       count(device_id) as user_num,
       avg (active_days_within_30) as avg_active_day,
       avg (question_cnt) as avg_question_cnt
from user_profile
where gender = 'female'
group by university
union
select gender,university,
       count(device_id) as user_num,
       avg (active_days_within_30) as avg_active_day,
       avg (question_cnt) as avg_question_cnt
from user_profile
where gender = 'male'
group by university;