public void updateGroup_schedule(Group_schedule gschedule)
	{
		PreparedStatement ps;
		try {
			if(gschedule.getId() > 0)
			{
				ps = con.prepareStatement("UPDATE group_schedule SET" +
						" group_id=?, schedule_id=?, teacher_id=? WHERE id=?");
				ps.setInt(4, gschedule.getId());
			}
			else
			{
				ps = con.prepareStatement("INSERT INTO group_schedule" +
						" (group_id, schedule_id, teacher_id) VALUES (?,?,?)");
			}
			ps.setInt(1, gschedule.getGroup());
			ps.setString(2, String.valueOf(gschedule.getSchedule().getId()));
			ps.setString(3, String.valueOf(gschedule.getTeacher().getId()));
			ps.executeUpdate();
			ps.close();
			
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}