/**
  * Update one person in database.
  * 
  * @param  integer  $id
  * @param  \Entities\Person  $person
  * @return void
  */
 public function update($id, Person $person)
 {
     $id = intval($id);
     $firstname = $this->pdo->quote($person->getFirstname());
     $lastname = $this->pdo->quote($person->getLastname());
     $this->pdo->exec("UPDATE persons SET firstname = {$firstname}, lastname = {$lastname} WHERE id = {$id}");
 }
 /**
  * Register function.
  * 
  * @param  string  $username
  * @param  string  $password
  * @param  \Entities\Person  $person
  * @return boolean
  */
 public function register($username, $password, Person $person)
 {
     $username = $this->pdo->quote($username);
     $password = $this->pdo->quote(sha1($password));
     $personId = intval($person->getId());
     $user = $this->pdo->query("SELECT * FROM users WHERE username = {$username}")->fetch();
     if (!empty($user)) {
         return false;
     }
     $this->pdo->exec("INSERT INTO users(username, password, persons_id) VALUES({$username}, {$password}, {$personId})");
     return true;
 }