try {
					String login = studentLog.textField.getText();
					String sql = "select * from student where nr_indeksu=?";
					Class.forName("org.h2.Driver");
					Connection connection = DriverManager.getConnection("jdbc:h2:tcp://localhost/~/test", "sa", "");;
				    PreparedStatement stmt = connection.prepareStatement(sql);
				    stmt.setString(1, login);
					ResultSet resultSet = stmt.executeQuery();
					while(resultSet.next()) {
						String ocena = resultSet.getString("ocena");
						System.out.println(ocena);
						label.setText(ocena);
					}
				} catch (ClassNotFoundException | SQLException e1) {
					// TODO Auto-generated catch block
					e1.printStackTrace();
				}