添加注释和warning: 总是在数据库中执行任何操作之前进行备份。做一些你不想做的事情很容易就会丢失大量数据，尤其是在处理DELETE 声明。此外，如果数据库使用InnoDB作为数据库引擎，则可以使用transactions 通过BEGIN, ROLLBACK, 和COMMIT.

您的查询已关闭，但您正在指定d 在您的DELETE 子句，该子句将导致中的行wp_term_taxonomy 也要删除。wp_term_taxonomy 是将术语与分类法联系起来的内容，这就是术语从类别中删除的原因。请尝试以下操作：

DELETE
    a, -- DELETE from posts
    b, -- DELETE from term relationships
    c  -- DELETE from postmeta
FROM wp_posts a
LEFT JOIN wp_term_relationships b ON ( a.ID = b.object_id )
LEFT JOIN wp_postmeta c ON ( a.ID = c.post_id )
LEFT JOIN wp_term_taxonomy d ON ( d.term_taxonomy_id = b.term_taxonomy_id )
LEFT JOIN wp_terms e ON ( e.term_id = d.term_id )
WHERE e.term_id = 378 AND DATEDIFF(NOW(), post_date) > 400;

• wp_posts 很明显，这就是WordPress存储帖子主要记录的地方
• wp_postmeta WordPress在其中存储与帖子相关的额外信息
• wp_term_relationships 定义post类型对象与术语的关联方式

最后一点注意：如果您使用代表其表名的别名，这将有助于您更容易理解像这样复杂的查询，当出现问题时，或者当您暂时不查看查询，然后返回查询时。使用更多描述性别名编写的查询示例如下：

DELETE
    p, -- DELETE from posts
    tr, -- DELETE from term relationships
    pm  -- DELETE from postmeta
FROM wp_posts p
LEFT JOIN wp_term_relationships tr ON ( p.ID = tr.object_id )
LEFT JOIN wp_postmeta pm ON ( p.ID = pm.post_id )
LEFT JOIN wp_term_taxonomy tt ON ( tt.term_taxonomy_id = tr.term_taxonomy_id )
LEFT JOIN wp_terms t ON ( t.term_id = tt.term_id )
WHERE t.term_id = 378 AND DATEDIFF(NOW(), post_date) > 400;

您必须添加“AND a.post\\u type=\'post\'”

delete a,b,c,d
FROM wp_posts a
LEFT JOIN wp_term_relationships b ON ( a.ID = b.object_id )
LEFT JOIN wp_postmeta c ON ( a.ID = c.post_id )
LEFT JOIN wp_term_taxonomy d ON ( d.term_taxonomy_id = b.term_taxonomy_id )
LEFT JOIN wp_terms e ON ( e.term_id = d.term_id )
WHERE e.term_id =378 AND DATEDIFF(NOW(), post_date) > 400
AND a.post_type=\'post\'