PDO行數混淆

Question

好吧，這讓我感到困惑，我想知道如果有人可以啓發我爲什麼它發生。我正在做一個登錄頁面，檢查數據庫中的匹配值，如果SELECT查詢返回一個帶有用戶名和密碼的匹配行，那麼它將返回1的行數。我現在編碼的方式是當我回顯變量存儲行計數它會回聲26出於某種原因，我不知道爲什麼。如果有人可以看看代碼，並解釋我是否做錯了什麼，或者如果這是正常的行爲，並且價值從何而來，我將不勝感激。

function checkLogin($conn,$myusername,$mypassword,$row,$row1){ 
    try { 
     $sql = "SELECT COUNT(*) FROM CLL_users WHERE user_name = 'user' AND password = 'XXXX'"; 
     if ($results = $conn->query($sql)) { 

      if($results->fetchColumn() > 0) { 

       $sql = "SELECT * FROM CLL_users WHERE user_name = 'user' AND password = 'XXXXX'"; 
       foreach ($conn->query($sql) as $row) 
       {    
        $rowCount = count($row); 
        echo $rowCount; 
        print ("Username: " . $row['user_name'] . "<br>"); 
        print ("Username: " . $row['password'] . "<br>"); 

        } 

        echo $count; 
      } 
     else { 
      print "NO ROWS"; 
     } 
     } 
     } catch (PDOException $e){ 
    echo 'Connection failed: ' . $e->getMessage(); 
} 

} 

Answer 1

function checkLogin($conn,$myusername,$mypassword,$row,$row1) 
{ 
    try 
    { 
     $sql = "SELECT COUNT(*) FROM CLL_users WHERE user_name = 'user' AND password = 'XXXX'"; 
     if ($results = $conn->query($sql)) 
     { 

      $count = $results->fetchColumn(); 
      echo "$count\n"; 

      if($count > 0) 
      { 
       $sql = "SELECT * FROM CLL_users WHERE user_name = 'user' AND password = 'XXXXX'"; 
       foreach ($conn->query($sql) as $row) 
       {    
        print ("Username: " . $row['user_name'] . "<br>"); 
        print ("Username: " . $row['password'] . "<br>");  
       } 
      } 
      else 
      { 
       print "NO ROWS"; 
      } 
     } 
    } 
    catch (PDOException $e) 
    { 
     echo 'Connection failed: ' . $e->getMessage(); 
    } 

} 

Answer 2

您的代碼，$rowCount = count($row);，計數列當前行中 - 由查詢返回的行數量不限。

在同一張紙條上，您正在迴應第二個計數相關變量，$count，但您既不聲明也不在代碼中增加它。它看起來像是應該計算循環行數的那個。如果這是事實，你應該將其設置爲$count = 0;循環之前，並在其中使用$count++;：

$count = 0; 
foreach ($conn->query($sql) as $row) { 
    print ("Username: " . $row['user_name'] . "<br>"); 
    print ("Username: " . $row['password'] . "<br>"); 
    $count++; 
} 
echo $count; 

此外，您正在使用PDO的rowCount之前，選擇用戶和你正確地使用它。你可以是結果只是存儲到一個變量，並用它來告訴你多少行接收：

$sql = "SELECT COUNT(*) FROM CLL_users WHERE user_name = 'user' AND password = 'XXXX'"; 
if ($results = $conn->query($sql)) { 
    $numRows = $results->fetchColumn(); 
    if($numRows > 0) { 
     ... rest of your code ....