PHP注意：未定义的变量：行

Question

我正在尝试处理这个错误，它显示通知未定义的变量行。这是我的代码：

<?php
  include('include/db.php');
  include('include/function.php');  
  if(isset($_GET['services'])){            
        $result=$Con->query("SELECT * FROM tbl_about_n_servciesub WHERE sub_id={$_GET['services']}");
        $row=mysqli_fetch_object($result);
  echo $row->description;
  }
?>