我有一個MySQL的代碼，我在面臨危機「mysqli_num_rows（）預計參數1被mysqli_result，串給出」

Question

這是我的代碼： 1）連接代碼 2）登錄頁面

<?php 
    ini_set("display_errors",1); 
    class connection //create a class for make connection 
    { 
    var $host = "localhost"; 
    var $username = "root"; 
    var $password = ""; 
    var $database = "myDb"; 
    var $myconn; 
    var $select; 
    var $query; 
    function database() //create a function for connect to database 
    { 
     $conn = mysqli_connect($this->host,$this->username,$this->password); 

     if(!$conn) // testing the connection 
     { 
      die ("Cannot connect to the database"); 
     } 
     else 
     { 
      $this->myconn = $conn; 
     } 
     mysqli_select_db($this->myconn,$this->database); //use php inbuil function for select database 

     if(mysqli_error($this->myconn)) //if error occured display the error message\\ 
     { 
      echo "Cannot find the database " . $this->database; 
     } 
     return $this->myconn; 
    } 
    function query($select) 
    { 
     $this->query= mysqli_query($this->myconn,$select)or die(mysqli_error($this->myconn)); 
    } 
    function fetchQuery() 
    { 
     return mysqli_fetch_array($this->query); 
    } 
    function closeConnection() //close the connection 
    { 
     mysqli_close($this->myconn); 
    } 
} 
?> 

和我正在處理它的頁面。

<?php 
$connection = new connection(); 
$connection->database(); 
if(isset($_POST['submit'])) 
{ 
    $user = $_POST['name']; 
    $pass = $_POST['password']; 
    $select = "SELECT * From tab_user where txt_uname ='$user' and txt_pass ='$pass' "; 
    $result = $connection->query($select); 
    $count = mysqli_num_rows($result); 
    if($count>0) 
    { 
     $row = $connection->fetchQuery(); 
     $name = $row['txt_full_name']; 
     echo $name; 
     $connection->closeConnection(); 
    } 
    else 
    { 
     echo 'Wrong Inputs.'; 

    } 
} 
?> 

<form method="post"> 
    <input type="text" name="name"> 
    <input type="password" name="password"> 
    <input type="submit" name="submit" value="submit"> 
</form> 

我面臨一個問題「mysqli_num_rows（）期望參數1是mysqli_result，字符串給定」。 我該如何解決它。請幫忙 。謝謝 ！！

Answer 1

試試這個

'.$user.' and '.$pass.' 

，而不是

'$user' and '$pass' 

Answer 2

您的查詢（）函數不返回任何東西，但你正在試圖與返回值來工作：

// In code: 
$result = $connection->query($select); 
$count = mysqli_num_rows($result); 
// In class: 
function query($select) 
    { 
     $this->query= mysqli_query($this->myconn,$select)or die(mysqli_error($this->myconn)); 
    } 

您可以執行以下操作：

mysqli_num_rows($connection->query); 

或者返回的結果，以及將其存儲：

function query($select) 
    { 
     return $this->query= mysqli_query($this->myconn,$select)or die(mysqli_error($this->myconn)); 
    }