题解 | #分组计算练习题#

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 
order by gender,university
#关键是最后一步排序依据不能少，前面都写好了提交发现报错，检查了几遍发现是没有写orderby这一步