题解 | #分组计算练习题#
分组计算练习题
http://www.nowcoder.com/practice/009d8067d2df47fea429afe2e7b9de45
Just AVG! :(
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 gender, university
，可以适当对关键信息加粗一点，比如关键技术、性能指标之类的。