题解 | #分组计算练习题#
分组计算练习题
http://www.nowcoder.com/practice/009d8067d2df47fea429afe2e7b9de45
SELECT gender, university, count(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;
- 这个题可以不用where，直接排序两个字段，并且用其中值唯一的ID做用户数统计
