code: private void onRelationalAttributes(List<RelationHolder> rlHolders, Row row, Table schemaTable)
      {
          // Iterate over relations
          if (rlHolders != null && !rlHolders.isEmpty())
          {
              for (RelationHolder rh : rlHolders)
              {
                  String relationName = rh.getRelationName();
                  Object valueObj = rh.getRelationValue();
  
                  if (!StringUtils.isEmpty(relationName) && valueObj != null)
                  {
                      if (valueObj != null)
                      {
                          NoSqlDBUtils.add(schemaTable.getField(relationName), row, valueObj, relationName);
                          KunderaCoreUtils.printQuery(
                                  "Add relation: relation name:" + relationName + "relation value:" + valueObj,
                                  showQuery);
                      }
                  }
              }
          }
      }
docs: Process relational attributes.
  
  @param rlHolders
  relation holders
  @param row
  kv row object
  @param schemaTable
  the schema table