public static HashSet<Answer> getAnswerRows() {
        Connection conn = ConnectionManager.getInstance().getConnection();
        
        String sql = "{call selectAnswerRows()}";

        try (PreparedStatement stmt = conn.prepareStatement(sql);
                ResultSet rs = stmt.executeQuery();) {

            HashSet<Answer> hashSet = new HashSet<Answer>();

            while (rs.next()) {
                Answer answerEntity = new Answer();
                answerEntity.setQuestionNo(rs.getString("questionNo"));
                answerEntity.setAnswerNo(rs.getString("answerNo"));
                answerEntity.setAnswer(rs.getString("answer"));
                answerEntity.setIsCorrect(rs.getBoolean("isCorrect"));

                hashSet.add(answerEntity);
            }
            return hashSet;
            
        } catch (SQLTransientConnectionException SQLtce) {
            return getAnswerRows();
        } catch (SQLTransientException SQLte) {
            return getAnswerRows();
        } catch (SQLException e) {
            System.err.println(e);
            return null;
        } finally {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }