题解 | #分组过滤练习题#
分组过滤练习题
https://www.nowcoder.com/practice/ddbcedcd9600403296038ee44a172f2d
select university,avg(question_cnt) as avg_question_cnt,avg(answer_cnt) as avg_answer_cnt from user_profile group by university having avg(question_cnt)<5 or avg(answer_cnt)<20
where 不能跟聚合函数作为筛选条件,但是having 可以 ,having一般跟在分组 group by后面