题解 | 统计复旦用户8月练题情况

select
    u1.device_id,
    '复旦大学' university,
    count(question_id) question_cnt,
    sum(if (result = 'right', 1,0)) right_question_cnt
from
    (
        select
            *
        from
            user_profile
        where
            university = "复旦大学"
    ) u1
    left join question_practice_detail q on u1.device_id = q.device_id
    and month (q.date) = 8
group by
    u1.device_id;