<?php
class Database {
    private $host = "localhost";
    private $username = "";
    private $password = "";
    private $db = "";
    private static $instance = null;
    /** @var mysqli */
    private $conn = null;

    private function  __construct() {
        $this->conn = new mysqli($this->host, $this->username, $this->password, $this->db);
        if (mysqli_connect_error()) {
            die('Connect Error (' . mysqli_connect_errno() . ') '
                    . mysqli_connect_error());
        }
        //hogy UTF-8-ban kommunikáljunk
        $this->conn->query("SET NAMES 'utf8'");
    }

    public function escapeString($string) {
        $string = $this->conn->real_escape_string($string);
        return $string;
    }

    /**
     * Singleton
     * @return Database
     */
    public static function getInstance() {
        if(Database::$instance == null) {
            Database::$instance = new Database();
        }
        return Database::$instance;
    }
    /**
     * Lefuttat egy selectet, és visszaadja asszoc tömbként a sorait
     * @param string $query
     * @return array
     */
    public function selectQuery($query) {
        $result = $this->conn->query($query);
        $array = array();
        //tömböt feltölt
        while ($sor = $result->fetch_assoc()) {
            $array[]=$sor;
        }
        return $array;
    }

    public function insertQuery($query) {
        $this->conn->query($query);
        //nem adunk vissza semmit
    }

    public function updateQuery($query) {
        $result = $this->conn->query($query);
        //változott sorok száma
        return $this->conn->affected_rows;
    }

}