mysql - sql 请求最大分组依据

Question

大家好，你们能帮我吗？ 请在下面的图像中找到输入和输出数据 因此，我需要编写sql请求以仅显示每个competent_question_id中的最大日期，并且还显示具有该日期的competent_answer_id的值(我也按response_id分组，但我将其隐藏在此处)

提前谢谢

SELECT response_id, competence_question_id, competence_answer_id, MAX(date_created)
FROM competence_vote_history
WHERE response_id = 53178
GROUP BY response_id, competence_question_id, competence_answer_id
ORDER BY response_id, competence_question_id

the table one with input data

the table two with output data

Answer 1

尝试以下查询以获得所需的结果。

SELECT competence_question_id, competence_answer_id, date_created, answer_value
FROM competence_vote_history i
WHERE response_id = 53178 
    AND date_created = (
        SELECT MAX(date_created) 
        FROM competence_vote_history 
        WHERE response_id = i.response_id 
        AND competence_question_id = i.competence_question_id)
ORDER BY response_id, competence_question_id