题解 | 分组计算练习题
分组计算练习题
https://www.nowcoder.com/practice/009d8067d2df47fea429afe2e7b9de45
SELECT gender, university,
count(device_id) 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 //分组做统计
ORDER BY gender, university //排序，order by在group by的后面，而且两个语句里面都是用逗号衔接
