mysql - 在MySQL中加入联接删除

Question

这是创建我的表的脚本:

CREATE TABLE clients (
   client_i INT(11),
   PRIMARY KEY (client_id)
);
CREATE TABLE projects (
   project_id INT(11) UNSIGNED,
   client_id INT(11) UNSIGNED,
   PRIMARY KEY (project_id)
);
CREATE TABLE posts (
   post_id INT(11) UNSIGNED,
   project_id INT(11) UNSIGNED,
   PRIMARY KEY (post_id)
);

在我的PHP代码中，删除客户端时，我要删除所有项目帖子:

DELETE 
FROM posts
INNER JOIN projects ON projects.project_id = posts.project_id
WHERE projects.client_id = :client_id;

posts表没有外键 client_id，只有 project_id。我想删除已传递 client_id的项目中的帖子。

现在无法正常工作，因为没有帖子被删除。

Answer 1

您只需要指定要从posts表中删除条目:

DELETE posts
FROM posts
INNER JOIN projects ON projects.project_id = posts.project_id
WHERE projects.client_id = :client_id

编辑:有关更多信息，您可以看到 this alternative answer