MySQL SELECT IN与子查询

Question

好吧，所以我在以下方面遇到了问题。我试图用两个子查询来做一个选择语句。 我需要做的基本上是以下内容。

满足以下条件的SELECT * FROM messages WHERE 。

条件1：

 SELECT id 
 FROM messages 
 WHERE `receiver` = 123510 && sender= 123457 && status != 3;

条件2：

 SELECT id 
 FROM messages 
 WHERE receiver = 123457 && sender = 123510 && status !=4;

我尝试执行以下操作：

SELECT * 
FROM messages 
WHERE id IN (
                 (
                     SELECT id 
                     FROM messages 
                     WHERE `receiver` = 123510 && sender= 123457 && status != 3
                 ),
                 (
                     SELECT id 
                     FROM messages 
                     WHERE receiver = 123457 && sender = 123510 && status !=4)
                  )  

但是当我这样做时，mysql带着子查询返回了超过1行...

关于如何解决这个问题有什么建议吗？

Answer 1

我认为这是您要寻找的：

SELECT *
FROM messages
WHERE (receiver = 123510 AND sender = 123457 AND status <> 3) OR
      (receiver = 123457 AND sender = 123510 AND status <> 4);

Answer 2

您将必须使用联合来分隔每个查询，或者将其作为两个单独的IN（以OR分隔）来完成。

SELECT * 
FROM messages 
WHERE id IN (
          SELECT id
          FROM messages
          WHERE `receiver` = 123510 and 
                sender= 123457 and 
                status != 3) or
          UNION
          SELECT id
          FROM messages 
          WHERE receiver = 123457 and 
          sender = 123510 and
          status !=4)

但实际上，这样做会更好。

SELECT * 
FROM messages 
WHERE (`receiver` = 123510 and 
       sender = 123457 and 
       status != 3) or
      (receiver = 123457 and 
       sender = 123510 and
       status !=4)