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(university) 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
university, gender;
按照大学和性别两个列来分组，中间用逗号隔开；
四舍五入使用ROUND()函数，该函数第一个参数是需要被四舍五入的变量，第二个参数是保留几位小数
