sql - 为什么这个 SQL 代码给出错误 1066(不是唯一的表/别名 : 'user' )?

Question

这是我的表结构:

错误信息是:

#1066 - Not unique table/alias: 'user'

以下是我的代码。

SELECT article.* , section.title, category.title, user.name, user.name
FROM article
INNER JOIN section ON article.section_id = section.id
INNER JOIN category ON article.category_id = category.id
INNER JOIN user ON article.author_id = user.id
LEFT JOIN user ON article.modified_by = user.id
WHERE article.id = '1'

Answer 1

第二次加入用户表时需要给它起一个别名

例如

SELECT article . * , section.title, category.title, user.name, u2.name 
FROM article 
INNER JOIN section ON article.section_id = section.id 
INNER JOIN category ON article.category_id = category.id 
INNER JOIN user ON article.author_id = user.id 
LEFT JOIN user u2 ON article.modified_by = u2.id 
WHERE article.id = '1'