public List<Vak> getVakkenVanStudent(long studentId) {
		List<Vak> vakken = new ArrayList<Vak>();
		List<Long> klasIds = new ArrayList<Long>();
		List<Long> vakIds = new ArrayList<Long>();
		try {
			PreparedStatement prepareStatement = manager
					.prepareStatement("SELECT klas_id FROM leerling_klas WHERE leerling_id = ?");
			prepareStatement.setLong(1, studentId);
			ResultSet resultSet = prepareStatement.executeQuery();

			while (resultSet.next()) {
				klasIds.add(resultSet.getLong(1));
			}
			PreparedStatement prepareStatement2 = manager
					.prepareStatement("SELECT vak_id FROM vak_klas WHERE klas_id = ?");
			for (Long klasId : klasIds) {
				prepareStatement2.setLong(1, klasId);
				ResultSet resultSet2 = prepareStatement2.executeQuery();

				while (resultSet2.next()) {
					vakIds.add(resultSet2.getLong(1));
				}
			}
			for (Long vakId : vakIds) {
				vakken.add(getVak(vakId));
			}
			return vakken;
		} catch (SQLException e) {
			e.printStackTrace();
			return vakken;
		}
	}