public boolean setCurrentPeriod(String period) {
        try {
            String stm = "UPDATE users SET city_name = ? WHERE login = 'admin'";
            PreparedStatement pst = waggrConnection.prepareStatement(stm);
            pst.setString(1,period);
            int i = pst.executeUpdate();
            if (i!=0) {
                pst.close();
                return true;
            }
            pst.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return false;
    }