Database::getInsertId PHP Method

    public function getInsertId()
    {
        return intval($this->conn->insert_id);
    }

 public static function INSERT()
 {
     $sql = "INSERT INTO `DocumentPart` (`id`, `__timestamp__`, `__operation__`) VALUES (NULL, " . time() . ", 'INSERT')";
     $result = Database::sql($sql);
     $id = Database::getInsertId();
     return self::ROW($id);
 }