Mysql Sql查询未返回最大值

我编写了以下查询，以获取具有最大问题id的值。但是我得到了图书id 2的问题id 14。我想要的是在图书id为2时获得第16期。并在图书id为3时发布图书id 15，以此类推

SELECT issue.issue_id AS issue_id, issue.issue_date, issue.student_id, books.availability,
    CASE WHEN NOW() > DATE_ADD(issue.issue_date, INTERVAL 20 DAY)
        THEN 10*DATEDIFF(NOW(), DATE_ADD(issue.issue_date, INTERVAL 20 DAY))
        ELSE 0 END AS fine_amount
        FROM issue
        INNER JOIN books
        ON issue.book_id=books.book_id
        WHERE books.book_id=2 
        HAVING MAX(issue.issue_id)

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按…使用订单。。限制1以获得最高值

SELECT issue.issue_id AS issue_id, issue.issue_date, issue.student_id, books.availability,
    CASE WHEN NOW() > DATE_ADD(issue.issue_date, INTERVAL 20 DAY)
        THEN 10*DATEDIFF(NOW(), DATE_ADD(issue.issue_date, INTERVAL 20 DAY))
        ELSE 0 END AS fine_amount
        FROM issue
        INNER JOIN books
        ON issue.book_id=books.book_id
        WHERE books.book_id=2 
        ORDER BY issue.issue_id DESC LIMIT 1

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Sql MAX示例，其中

具有

和

WHERE

请参见。反向比较会更有效