题解 | 分组过滤练习题
分组过滤练习题
https://www.nowcoder.com/practice/ddbcedcd9600403296038ee44a172f2d
select
university,
round(avg(question_cnt),3) as avg_question_cnt,
round(avg(answer_cnt),3) as avg_answer_cnt
from user_profile
group by university
having avg_question_cnt <5 or avg_answer_cnt < 20
;
这题的解题思路是先分组聚合再筛选,优先级:where>group by>having