| 
<?phprequire_once './db.php';
 
 /** Usually you do this */
 // $userId = filter_input(INPUT_GET, 'user_id', FILTER_VALIDATE_INT);
 /** For the sake of demo I am hard coding */
 $userId = 2;
 try {
 $userQuery = $pdo->prepare("
 DELETE FROM
 `users`
 WHERE
 `id` = :user_id
 ");
 $userQuery->execute([
 ':user_id'      => $userId
 ]);
 
 /** If no records were deleted then it will throw exception */
 if ($userQuery->rowCount() < 1) {
 throw new Exception('No records deleted.');
 }
 
 echo 'Deleted successfully.';
 } catch (Exception $e) {
 /** Handle all your errors here */
 exit($e->getMessage());
 }
 
 |