public static function makeUpdateSQL()
    {
        $tableName = self::getTableName();
        $setClause = "";
        $whereClause = "";
        $keysCount = count(self::$fields);
        $iterations = 1;

        foreach(self::$fields as $key => $val)
        {
            if($key == "id") {
                $whereClause = " WHERE id = ".$val;
            }
            else if($key != "result") {
                $setClause = $setClause.$key." = '".$val."'";

                if($keysCount > 2 && $iterations < $keysCount) {
                    $setClause = $setClause.", ";
                }
            }
            $iterations++;
        }

        $sql = "UPDATE ".$tableName." SET ".$setClause.$whereClause;

        return $sql;
    }