# $578. 查询回答率最高的问题
# https://leetcode-cn.com/problems/get-highest-answer-rate-question/

# SQL架构
Create table If Not Exists SurveyLog (id int, action varchar(255), question_id int, answer_id int, q_num int, timestamp int);
Truncate table SurveyLog;
insert into SurveyLog (id, action, question_id, answer_id, q_num, timestamp) values ('5', 'show', '285', null, '1', '123');
insert into SurveyLog (id, action, question_id, answer_id, q_num, timestamp) values ('5', 'answer', '285', '124124', '1', '124');
insert into SurveyLog (id, action, question_id, answer_id, q_num, timestamp) values ('5', 'show', '369', null, '2', '125');
insert into SurveyLog (id, action, question_id, answer_id, q_num, timestamp) values ('5', 'skip', '369', null, '2', '126');

# Write your MySQL query statement below
select
    question_id as survey_log
from
    (
        select
            question_id,
            sum(if(action = 'answer', 1, 0)) as answercnt,
            sum(if(action = 'show', 1, 0)) as showcnt
        from
            SurveyLog
        group by
            question_id
    ) tmp
order by
    (answercnt / showcnt) desc
limit
    1;

# clean-up
drop table SurveyLog;