rowCount where和OR与MySQL和PHP

我想计算两个成员之间的会话数。当用户1访问用户2的配置文件时，我看到可见的结果。但是，当用户2访问配置文件1时，我没有结果。rowCount where和OR与MySQL和PHP

public function getNumberConversations($sender, $receiver) { 

    $st = Database::getDatabase()->prepare("SELECT id, sender, receiver 
     FROM conversation 
     WHERE sender = ? AND receiver = ? 
     OR receiver = ? AND sender = ? 
    "); 

    $st->execute(array($sender, $receiver, $receiver, $sender)); 

    return $st->rowCount(); 

    }

来源

2017-08-22 Manudog

'WHERE（发件人=和接收器=？）或' – JYoThI

另外，你要互换的发送者和接收者的两倍（接收器=和发件人=？）：在查询和在数组中。净结果：根本没有交换，并且重复子句'WHERE（sender = $ sender AND receiver = $ receiver）OR（receiver = $ receiver AND sender = $ sender）' – bracco23

我认为在这种情况下括号不是问题 – etsa

我想你应该改变

$st->execute(array($sender, $receiver, $receiver, $sender));

与

$st->execute(array($sender, $receiver, $sender, $receiver));

你的情况括号OK（和优先级）

来源

2017-08-22 09:01:55 etsa

使用括号为条件

public function getNumberConversations($sender, $receiver) { 

    $st = Database::getDatabase()->prepare("SELECT id, sender, receiver 
     FROM conversation 
     WHERE (sender = ? AND receiver = ?) 
     OR (receiver = ? AND sender = ?) 
    "); 

    $st->execute(array($sender, $receiver, $sender, $receiver)); // also notice this 

    return $st->rowCount(); 

    }

来源

2017-08-22 09:01:35

I已经尝试过但不起作用 – Manudog

然后在你的问题中更新它，否则每个人都会有相同的答案 –

您需要为分离条件设置广告支架。你也交换条件，所以它会变得相同。试试以下的答案：

public function getNumberConversations($sender, $receiver) { 

    $st = Database::getDatabase()->prepare("SELECT id, sender, receiver 
     FROM conversation 
     WHERE (sender = ? AND receiver = ?) 
     OR (receiver = ? AND sender = ?) 
    "); 

    $st->execute(array($sender, $receiver, $sender, $receiver)); //<----change here also 

    return $st->rowCount(); 

    }

来源

2017-08-22 09:02:07

rowCount where和OR与MySQL和PHP

回答

相关问题