mysql - 使用 AND & OR 运算符的 MySQL 查询

Question

下面的查询会加载所有对话，但是，我只想加载两个人之间的对话。

SELECT * FROM msg 
WHERE senderid = '{$sender}' 
OR recid = '{$recipient}' 
OR recid = '{$sender}' 
OR senderid = '{$recipient}' 
order by id asc

我将如何一起使用 AND & OR 运算符？下面的工作吗？

SELECT * FROM msg 
WHERE senderid = '{$sender}' 
AND recid = '{$recipient}' 
OR recid = '{$sender}' 
AND senderid = '{$recipient}' 
order by id asc

Answer 1

一起使用ANDandOR时，请使用括号对您的逻辑进行分组，并确保它符合您的预期：

SELECT * FROM msg 
WHERE (senderid = '{$sender}' AND recid = '{$recipient}')
OR    (recid = '{$sender}' AND senderid = '{$recipient}')
order by id asc

Answer 2

如下请见。

SELECT * FROM msg 
WHERE (senderid = '{$sender}' AND recid = '{$recipient}') 
OR (recid = '{$sender}' AND senderid = '{$recipient}') 
order by id asc