mysql - 子查询的 SQL 别名

Question

我对以下查询有疑问：

SELECT * FROM (
  (SELECT * FROM Images 
   WHERE create_user_id=:user_id) RIGHT INNER JOIN 
  (SELECT * FROM PhotoGallery) ON id=centity_id
 )
 ORDER BY centity_id;

我收到 1248 - 每个派生表都必须有自己的别名错误，我知道我需要为这些表提供别名，但无论我做什么，我总是会出错。谁能帮我解决这个问题？非常感谢！

Answer 1

If you are doing a select *, you don't need to do a sub-query.

SELECT * FROM Images 
  RIGHT OUTER JOIN PhotoGallery ON id=centity_id
WHERE create_user_id = :user_id
ORDER BY centity_id;

Answer 2

尝试这个

SELECT * 
  FROM Images i RIGHT JOIN
       PhotoGallery p ON i.id=p.centity_id
 WHERE i.create_user_id=:user_id
 ORDER BY p.centity_id

根据您的 DDL 和您所需的输出连接可能是RIGHT,INNER或LEFT, 但不是RIGHT INNER JOIN

Answer 3

您的子查询需要别名。就像是：

SELECT * FROM (
  (SELECT *
   FROM Images 
   WHERE create_user_id=:user_id
  ) i RIGHT INNER JOIN 
  PhotoGallery pg
  ON i.id=pg.centity_id
 )
 ORDER BY centity_id;

Answer 4

我从未听说过支持“RIGHT INNER JOIN”的 dbms。选择其中之一

• 内连接，或
• 右外连接，或
• RIGHT JOIN（应该与 RIGHT OUTER JOIN 相同）。