题解 | #分组计算练习题#

 select gender ,university,count(gender) as user_num ,round(avg(active_days_within_30), 1) as avg_active_day,round(avg(question_cnt), 1) as avg_question_cnt from  user_profile group by gender ,university

#  SELECT gender,university,COUNT(*) user_num, round(avg(active_days_within_30),1) AS avg_active_day, ROUND(avg(question_cnt),1) AS avg_question_cnt FROM user_profile GROUP BY gender,university;