// Main failas

<?php

require './view/form.php';
require './model/datbase.class.php';


if (isset($_POST["submitButton"])) {
    $db = new Database;
    $query = "INSERT INTO `lentele` (`name`, `surname`, `email`, `city`) "
            . "VALUES('{$_POST['vardas']}', '{$_POST['pavarde']}', '{$_POST['pastas']}', '{$_POST['miestas']}')";
    $db->executeQuery($query);
    }

?>

// klases failas
<?php

class Database {

    protected $con = null;
    protected $result = null;

    public function __construct() {
        $this->dbconnect();
    }

    private function dbconnect() {
        if (!isset($this->con)) {
            $hostname = "localhost";
            $username = "root";
            $password = "kaunassql";
            $database = "Duomenys";
            $this->con = new mysqli($hostname, $username, $password, $database);
        }

        if ($this->con === false) {

            return mysqli_connect_error();
        }
        else {
            echo "connected" . "<br>";
        }
    }

    public function executeQuery($query) {
        $this->result = $this->con->query($query);
    }

    public function getRow() {
        return $this->result->fetch_assoc();
    }

    public function getRowsNum() {
        return $this->result->num_rows;
    }

}