警告：mysqli_fetch_array（）期望参数1为mysqli_result，布尔值为*

Question

我正在创建一个Web系统，但是从用户表中登录用户时出错。

  

警告：mysqli_fetch_array（）期望参数1为mysqli_result，   在第13行的D：\ xampp ...... \ includes \ login_inc.php中给出的布尔值。

index.php

<form id="main-form" action="includes/login_inc.php" method="post">
                <p id="p-login">Please Log in to use the CRM.</p>
                        <label for="user">Email</label> 
                        <input id="username" type="text"  name="username" placeholder="Username">                    
                        <label for="password">Password</label>
                        <input id="password" type="password"  name="password" placeholder="Password">        

                        <button type="submit" name="login">Log in</button>                                            
                <p id="signup-txt">Don't have an account??.<a href="signup.php">Sign Up</a> here.                          
            </form>

login_inc.php

    <?php
   require 'dbconnect.php';

   session_start();

   if($_SERVER["REQUEST_METHOD"] == "POST") {

      $myusername = mysqli_real_escape_string($conn,$_POST['username']);
      $mypassword = mysqli_real_escape_string($conn,$_POST['password']); 

      $sql = "SELECT id FROM users WHERE username = '$myusername' and passcode = '$mypassword';";
      $result = mysqli_query($conn,$sql);
      $row = mysqli_fetch_array($result,MYSQLI_ASSOC);
      $active = $row['active'];

      $count = mysqli_num_rows($result);

      if($count == 1) {
         session_register("myusername");
         $_SESSION['login_user'] = $myusername;

         header("location: welcome.php");
      }else {
         $error = "Your Login Name or Password is invalid";
      }
   }
?>