class Database{
        private $db;

        const sql_host = "localhost";
        const sql_base = "tetbase";
        const sql_user = "root";
        const sql_pass = "";

        public function __construct() {
            $mysqli = @new mysqli(self::sql_host, self::sql_user, self::sql_pass, self::sql_base);
            if(!$mysqli->connect_error) {
                $this->db = $mysqli;
                $this->db->query("SET NAMES 'utf8'");
                return $this->db;
            } else exit("<strong>[Error]</strong> MySQL connection failed");
        }

        public function query($sql) {
            return $this->db->query($sql);
        }

        public function assoc($result) {
            if(!empty($result)) {
                return $result->fetch_assoc();
            } else return false;
        }

        public function num_rows($query) {
            if(!empty($query)) {
                return $query->num_rows;
            } else return false;
        }