题解 | 验证刷题效果，输出题目真实通过率

select
    user_id,
    count(distinct if (result_info = 1, question_id, null)) / count(distinct question_id) as question_pass_rate,
    count(if (result_info = 1, question_id, null)) / count(done_time) as pass_rate,
    count(done_time) / count(distinct question_id) as question_per_cnt
from
    done_questions_record
group by
    user_id
having
    question_pass_rate > 0.6