#分组计算练习题#
分组计算练习题
https://www.nowcoder.com/practice/009d8067d2df47fea429afe2e7b9de45
需要重写
SELECT
gender, university,
COUNT(device_id) 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
遇到的问题：
- 还不够清楚group by
- 还不太熟悉在SELECT写多行函数
- 参考题解写完后，发现忘记写了FROM