@Override
      public boolean isSigned(int param) {
        try {
          return Integer.parseInt(parameters.get(param)) < 0;
        } catch (Exception e) {
          return false;
        }
      }
save the SQL parameters as (paramLoc,paramValue) pairs.
iotdb-client/jdbc/src/main/java/org/apache/iotdb/jdbc/IoTDBPreparedStatement.java