public void logIn(String username, String password) throws SQLException {
		PreparedStatement statement = connection.prepareStatement("SELECT Password, IsManager FROM Users " +
                "WHERE Username = ?");
		statement.setString(1, username);
		ResultSet result = statement.executeQuery();
		if (!result.next() || !result.getString(1).equals(password)) {
            return;
        }
		this.username = username;
        isManager = result.getBoolean(2);
	}