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
group by gender, university
order by gender;

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

group by gender, university/该子句将 user_profile 表中的数据按照 gender 和 university 的不同组合进行分组。

order by gender;/ORDER BY 子句用于对查询结果进行排序。