题解 | #分组计算练习题#
分组计算练习题
https://www.nowcoder.com/practice/009d8067d2df47fea429afe2e7b9de45
select gender,university,count(device_id) as user_num, avg(active_days_within_30) as avg_active_days_within_30, avg(question_cnt) as avg_question_cnt from user_profile group by university,gender
题目要求:按照gender university顺序输出按照gender。university分成的组别
先按照要求统计处device_id 的数量,
然后依次统计