// javadoc is inherited
  public boolean nullifyForeignKey(SecondaryDatabase db, DatabaseEntry dataEntry)
      throws DatabaseException {

    Object data = dataBinding.entryToObject(dataEntry);
    data = nullifyForeignKey(data);
    if (data != null) {
      dataBinding.objectToEntry(data, dataEntry);
      return true;
    } else {
      return false;
    }
  }
  // javadoc is inherited
  public void objectToData(E object, DatabaseEntry data) {

    D dataObject = objectToData(object);
    dataBinding.objectToEntry(dataObject, data);
  }