ORM get specific columns

[Ayman250]

Using the ORM library is it possible to only retrieve specific columns? I have a table with several columns 2 of which contain a huge string that is only used in specific situations.

For now I have to use a prepared statement for this case:

  auto clientPtr = drogon::app().getDbClient("psql");
  auto f = clientPtr->execSqlAsyncFuture(
      "SELECT columns... WHERE key = $1, key);
  auto result = f.get();  // Block until we get the result or catch the exception;
  std::vector<drogon_model::db::Table> data;
  for (auto row : result) {
    drogon_model::db::table td(row, -1);
    data.push_back(td);
  }

Is there a way I can use the ORM library and prevent postgres from retrieving the two columns.

Example:
auto training_data = td_mapper.onlyColumns(columnlist...).findByPrimaryKey(trainingdataid);

Hopefully this question makes sense...