题解 | 分组过滤练习题

select
    university,
    avg_question_cnt,
    avg_answer_cnt
from
    (
        select
            up.university,
            AVG(up.question_cnt) as avg_question_cnt,
            AVG(up.answer_cnt) as avg_answer_cnt
        from
            user_profile up
        group by
            up.university
    ) ut
where
    avg_question_cnt < 5
    or avg_answer_cnt < 20