<?php

class Database
{
    /**
     * @var
     */
    private $link;

    /**
     * Database constructor.
     */
    public function __construct()
    {
        $this->connect();
    }


    /**
     * @return $this
     */
    private function connect()
    {
        $config = require_once 'config.php';


        $dsn = 'mysql:host='.$config['host'].';db_name='.$config['db_name'].';charset='.$config['charset'];

        $this->link = new PDO($dsn, $config['username'], $config['password']);

        return $this;
    }


    /**
     * @param $sql
     * @return mixed
     */
    public function execute($sql)
    {
        $sth = $this->link->prepare($sql);

        return $sth->execute();

    }

    /**
     * @param $sql
     * @return array
     */
    public function query($sql)
    {
        $sth = $this->link->prepare($sql);

        $sth->execute();


        $result = $sth->fetchAll(PDO::FETCH_ASSOC);

        if($result === false){
            return [];
        }

        return $result;
    }
}

$db = new Database();

$db->execute("INSERT INTO `user` SET `username`='Pavel', `password`='444444', `date`=".time());