MySQL删除较旧的记录

Question

我有成千上万的记录（包括重复的帖子），所以现在我想根据日期删除旧记录（只留下最新记录）。

我的代码下面给出

DELETE a.* 
FROM dle_post AS a 
    INNER JOIN (
     SELECT title, MIN(id) AS min_id 
     FROM dle_post 
     GROUP BY title 
     HAVING COUNT(*) > 1 
    ) AS b ON b.title = a.title 
AND b.min_id <> a.id 

的问题是ID，它随机记录的基础。我非常感谢你的帮助！

Answer 1

如果你想以日期为基础，你应该在子查询中使用MAX(date)。

DELETE a.* 
FROM dle_post AS a 
    INNER JOIN (
     SELECT title, MAX(date) AS maxdate 
     FROM dle_post 
     GROUP BY title 
     HAVING COUNT(*) > 1 
    ) AS b 
ON b.title = a.title 
AND a.date < b.maxdate 

Answer 2

刚刚创建SELECT查询要删除的帖子，并把和子查询中：

DELETE FROM dle_post WHERE id IN (SELECT id FROM dle_post WHERE ...) 

这是更具可读性和可维护性。