PHP-浏览器中的SQL查询问题不显示搜索结果

Question

在我的网络应用中，我有朋友搜索，我也不知道为什么，但是当我编写要搜索的用户名时，它没有显示错误，浏览器也没有显示任何内容。谁能帮助我找到该错误？ ：D我的代码如下：

<div class="input">
    <input type="text" class="finder" value="Find friends by username" name="friends">
    </div>
    <div class="friends"> 
    <?php 
     require_once "connect.php";
     mysqli_report(MYSQLI_REPORT_STRICT);
     $connection= mysqli_connect($host, $db_user, $db_password, $db_name);
     if(mysqli_connect_errno()) {
       echo "Server error. Try again later.";
     } else {
       $friends = $_POST['friends'];
     $result=$connection->query("SELECT username FROM users WHERE username = '$friends'");
     $row = mysqli_fetch_assoc($result);
     $username = $row['username'];
     $how_much_friends = $result->num_rows;
     if($how_much_friends=0) {
         $_SESSION['e_friends']= '<span style="color:white"> We did not found your friends on CD Messenger. </span>';
     } else {
       while($row) {
           if (isset($_SESSION['e_friends']))
           {
           echo $_SESSION['e_friends'];
           unset($_SESSION['e_friends']);
           } else {
            echo "<div>" .  $username . "</div>";
           }
       }

     }

     }
       $connection->close();
    ?>
    </div>