select gender, university, count(*) as user_num, avg(active_days_within_30) as avg_active_day, avg(question_cnt) as avg_question_cnt from user_profile group by university, gender 本题需要对不同大学不同性别的学生进行统计。使用group by university, gender 将表记录分为大学不同性别不同的组,利用count(*) as user_name, avg() as xxx 函数统计需要的数据并...