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
笔记:where 和 having 都是条件语句,where放到分组前面,只能用原始条件,having放到分组后面,只能用分组后的条件。
有不对的地方大佬指正,感谢