说明 从 survey_log 表中获得回答率最高的问题survey_log 表包含这些列：id action question_id answer_id q_num timestamp。id 表示用户 id；action 有以下几种值：showanswerskip；当 action 值为 answer 时 answer_id 非空而 action 值为 show 或者 skip 时 answer

以下是查询具有最高回答率的问题的SQL查询：

SELECT question_id, COUNT(*) AS total_count,
       COUNT(CASE WHEN action = 'answer' THEN 1 END) AS answer_count,
       COUNT(CASE WHEN action = 'answer' AND answer_id IS NOT NULL THEN 1 END) AS answered_count,
       COUNT(CASE WHEN action = 'show' OR action = 'skip' THEN 1 END) AS skipped_count,
       COUNT(CASE WHEN action = 'answer' THEN 1 END) / COUNT(*) AS answer_rate
FROM survey_log
GROUP BY question_id
ORDER BY answer_rate DESC
LIMIT 1;

该查询使用了GROUP BY子句来按question_id分组，并使用COUNT函数计算总回答数，回答数和显示/跳过数。然后，使用CASE语句将不同的action值进行计数，并计算回答率。最后，使用ORDER BY和LIMIT子句找到回答率最高的问题