题解 | #分组计算练习题#
分组计算练习题
https://www.nowcoder.com/practice/009d8067d2df47fea429afe2e7b9de45
先给出结果：
select gender, university, count(id) user_num, round(avg(active_days_within_30), 1) avg_active_day, round(avg(question_cnt), 1) avg_question_cnt from user_profile group by gender,university
分析：
1、性别和大学分组：group by gender,university
2、计数count(id)
3、平均数求30天内和发帖（保留一位小数并四舍五入）
round(avg(active_days_within_30), 1)
round(avg(question_cnt), 1)
