code: private DataColumnsDao getDataColumnsDao() {
          DataColumnsDao dataColumnsDao = null;
          try {
              dataColumnsDao = DaoManager.createDao(featureDao.getDb().getConnectionSource(), DataColumns.class);
              if (!dataColumnsDao.isTableExists()) {
                  dataColumnsDao = null;
              }
          } catch (SQLException e) {
              dataColumnsDao = null;
              Log.e(FeatureOverlayQuery.class.getSimpleName(), "Failed to get a Data Columns DAO", e);
          }
          return dataColumnsDao;
      }
docs: Get a Data Columns DAO
  
  @return data columns dao