PDO行数混淆

Question

好吧，这让我感到困惑，我想知道如果有人可以启发我为什么它发生。我正在做一个登录页面，检查数据库中的匹配值，如果SELECT查询返回一个带有用户名和密码的匹配行，那么它将返回1的行数。我现在编码的方式是当我回显变量存储行计数它会回声26出于某种原因，我不知道为什么。如果有人可以看看代码，并解释我是否做错了什么，或者如果这是正常的行为，并且价值从何而来，我将不胜感激。

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

您的代码，$rowCount = count($row);，计数列当前行中 - 由查询返回的行数量不限。

在同一张纸条上，您正在回应第二个计数相关变量，$count，但您既不声明也不在代码中增加它。它看起来像是应该计算循环行数的那个。如果这是事实，你应该将其设置为$count = 0;循环之前，并在其中使用$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，选择用户和你正确地使用它。你可以是结果只是存储到一个变量，并用它来告诉你多少行接收：

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