PHP alterando mysql_query antigo para PDO

<?php

    $query = "UPDATE people 
             SET price=?, 
                 contact=?, 
                 fname=?, 
                 lname=? 
              WHERE id=? AND 
                    username=?";
    $stmt = $dbh->prepare($query);
    $stmt->bindParam(1, $price);
    $stmt->bindParam(2, $contact);
    $stmt->bindParam(3, $fname);
    $stmt->bindParam(4, $lname);
    $stmt->bindParam(5, $id);
    $stmt->bindParam(6, $username);    
    $stmt->execute();

?>