rowCount where和OR與MySQL和PHP

我想計算兩個成員之間的會話數。當用戶1訪問用戶2的配置文件時，我看到可見的結果。但是，當用戶2訪問配置文件1時，我沒有結果。rowCount where和OR與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(); 

    }

來源

2017-08-22 Manudog

'WHERE（發件人=和接收器=？）或' – JYoThI

另外，你要互換的發送者和接收者的兩倍（接收器=和發件人=？）：在查詢和在數組中。淨結果：根本沒有交換，並且重複子句'WHERE（sender = $ sender AND receiver = $ receiver）OR（receiver = $ receiver AND sender = $ sender）' – bracco23

我認爲在這種情況下括號不是問題 – etsa

我想你應該改變

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

與

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

你的情況括號OK（和優先級）

來源

2017-08-22 09:01:55 etsa

使用括號爲條件

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(); 

    }

來源

2017-08-22 09:01:35

I已經嘗試過但不起作用 – Manudog

然後在你的問題中更新它，否則每個人都會有相同的答案 –

您需要爲分離條件設置廣告支架。你也交換條件，所以它會變得相同。試試以下的答案：

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(); 

    }

來源

2017-08-22 09:02:07

rowCount where和OR與MySQL和PHP

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