public void printAllUsers() {
		try {
			ResultSet result = statement.executeQuery("SELECT * from users");
			while(result.next()) {
				System.out.println(result.getInt("user_id"));
				System.out.println(result.getString("login"));
				System.out.println(result.getString("password"));
				System.out.println(result.getString("role"));
			}
		} catch (SQLException e) {
			System.out.println("cant read from database.");
		}
		
	}