public static HashSet<Integer> testAtt(ResultSet rs, double percent) throws SQLException {
        int columnCount = rs.getMetaData().getColumnCount();
        int[] testAtt = new int[columnCount];
        int rowCount = 0;
        HashSet<Integer> passAtt = new HashSet<>();
        while (rs.next()) {
            for (int i = 1; i < columnCount + 1; i++) {
                if (rs.getString(i) == null) {
                    testAtt[i]++;
                }
            }
            rowCount++;
        }
        for (int i = 0; i < columnCount; i++) {
            if ((double) testAtt[i] / (double) rowCount > percent) {
                passAtt.add(i + 1);
            }
        }
        rs.close();
        return passAtt;
    }