class SQL {
    protected $handler;
    protected $hostname = 'localhost';
    protected $password = '';
    protected $username = 'root';
    protected $dbname   = 'test';

    public function __construct() {
        try {
            $this->handler = new PDO("mysql:host={$this->hostname};dbname={$this->dbname}", $this->username, $this->password);
        }
        catch(PDOException $e) {
            echo $e->getMessage();
        }
    }

    public function insert($table,$rows,$values){
       return $this->handler->exec("INSERT INTO ".$table."(".$rows.") VALUES ('".$values."')");
    }
}

$sql = new SQL();
$sql->insert("users", "username,password", "'hisham', 'startimes'");