Flutter floor db cannot define return type

Question

This is my model.

class JoinedResults {
  final int? id;
  final int? question_id;
  final String? question_text;
  final String? question_type;
  final bool? is_mandatory;
  final int? correct_option_id;
  final int? option_id;
  final String? option_list_text;

  JoinedResults({
     this.id,
     this.question_id,
     this.question_text,
     this.question_type,
     this.is_mandatory,
     this.correct_option_id,
     this.option_id,
     this.option_list_text,
  });
}



 // daos.dart
import 'package:floor/floor.dart';
import 'package:rasta_app/bloc/questions_model.dart';

@dao
abstract class QuestionDao {

@Query('SELECT Question.question_id, Question.question_text, Question.question_type, Question.is_mandatory, Question.correct_option_id, OptionLists.option_id,OptionLists.option_list_text FROM Question INNER JOIN OptionLists ON Question.question_id = OptionLists.questionId')
  Future<List<JoinedResults>> getAllQuestionsWithOptions();    
}

This is the error i am facing, Can not define return type

Future<List<JoinedResults>> getAllQuestionsWithOptions();

I am using floor database in flutter i have two Tables One is "Question" and Second is "OptionLists" and Now i want to implement inner Join Query at both tables and then fetch the data and map it into a custom data type list named "JoinedResults" but i am keep getting below error :

This is the error i am facing

Can not define return type package:rasta_app/bloc/question_dao.dart:14:31

 Future<List<JoinedResults>> getAllQuestionsWithOptions();

Answer 1

You can't return some object from DAO that is not part of DAO. So you should handle it above DAO. As an option you should use streams. more detail here: Floore streams

example1, example2

Answer 2

I've never used floor, but I think the problem is you're trying to make DAO out of a plain dart class. You should make your JoinedResult class an entity, or a view. Refer to https://pinchbv.github.io/floor/database-views/ for more documentation