题解 | #查找学校是北大的学生信息#
分组过滤练习题
http://www.nowcoder.com/practice/ddbcedcd9600403296038ee44a172f2d
select gender,university, count(1) as user_num, round(avg(active_days_within_30),1) as avg_activi_day, round(avg(question_cnt),1) as avg_question_cnt from user_profile group by gender, university;
这里面我直接count(1) as user_num 会有什么问题吗？
