code: public static int queryForInt(Statement stmt, String sql, int nullvalue) {
      try {
        ResultSet rs = stmt.executeQuery(sql);
        try {
          if (!rs.next())
            return nullvalue;
          
          return rs.getInt(1);
        } finally {
          rs.close();
        }
      } catch (SQLException e) {
        throw new DukeException(e);
      }
    }
docs: Runs a query that returns a single int.