题解 | #浙江大学用户题目回答情况#

-- 子查询
select device_id, question_id, result
from question_practice_detail
where device_id in (
        select  device_id
        from user_profile
        where university = '浙江大学')
order by question_id;
-- 内连接（交集）
select q.device_id, q.question_id, q.result
from question_practice_detail as q
    inner join user_profile as u
    on q.device_id = u.device_id
    and u.university = '浙江大学'
order by question_id;