Here’s my code of quiz_screen.dart where i want to display the questions and choices:

import 'package:flutter/material.dart';
import '../models/fetch_questions_and_choices.dart';

class QuizScreen extends StatefulWidget {
  static const routeName = '/quiz';
  const QuizScreen({super.key});

  @override
  State<QuizScreen> createState() => _QuizScreenState();
}

class _QuizScreenState extends State<QuizScreen> {

  late Future<List<Question>> _futureQuestions;
  Map<int, int> _selectedChoice = {};


  @override
  void initState() {
    super.initState();
    _futureQuestions = fetchQuestionAndChoice();
  }

  void _selectChoice(int questionId, int choiceId){
    setState(() {
      _selectedChoice[questionId] = choiceId;
    });
  }

  int _calculateScore(List<Question> questions) {
  int score = 0;
  for (var question in questions) {
    if (_selectedChoice[question.id] != null) {
      Choice selectedChoice = question.choices.firstWhere(
        (choice) => choice.id == _selectedChoice[question.id],
        orElse: () => Choice(id: 0, questionId: question.id, choiceText: '', isCorrect: false),
      );
      if (selectedChoice.isCorrect) {
        score++;
      }
    }
  }
  return score;
}


void _showScore(BuildContext context, int score){
  showDialog(context: context, builder: (context) => AlertDialog(
    title: Text('Quiz Completed!'),
    content: Text('Your Score is $score'),
    actions: [
      TextButton(onPressed: () => Navigator.of(context).pop(), child: Text("OK"))
    ],
  ));
}

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Quiz'),
      ),
      body: FutureBuilder(future: _futureQuestions, builder: (context, snapshot) {
        if(snapshot.connectionState == ConnectionState.waiting){
          return Center(
            child: CircularProgressIndicator(),
          );
        }
        else if(snapshot.hasError){
          return Center(
            child: Text('Error: ${snapshot.error}'),
          );
        }
        else if(snapshot.data == null || snapshot.data!.isEmpty){
          return Center(
            child: Text('No Questions Added Yet.'),
          );
        }
        else{
          List<Question> questions = snapshot.data!;

        return Column(
          children: [
            Expanded(
              child: ListView.builder(
                itemCount: questions.length,
                itemBuilder: (context, i) {
                  Question question = questions[i];
                  return Card(
                    child: Column(
                      children: [
                        Text(
                          question.questionText,
                          style: TextStyle(
                            fontSize: 28,
                            fontWeight: FontWeight.bold
                          ),
                        ),
                        ...question.choices.map(
                          (choice) => RadioListTile(
                            title: Text(choice.choiceText),
                            value: choice.id, 
                            groupValue: _selectedChoice[question.id], 
                            onChanged: (value) {
                              _selectChoice(question.id, value!);
                            }
                            )
                        )
                      ],
                    ),
                  );
                },),
                ),

                
                ElevatedButton(onPressed: () {
                  int score = _calculateScore(questions);
                  _showScore(context, score);
                }, child: Text("Submit"))
          ],
        );
        }
        
      }),
    );
  }
}

And this is my database_services file:

import 'package:sqflite/sqflite.dart';
import 'package:path/path.dart';

class DBHelper {
  static final DBHelper _instance = DBHelper._internal();
  factory DBHelper() => _instance;
  static Database? _database;

  DBHelper._internal();

  Future<Database> get database async {
    if (_database != null) return _database!;
    _database = await _initDB();
    return _database!;
  }

  Future<Database> _initDB() async {
    String path = join(await getDatabasesPath(), 'quiz_app.db');
    return await openDatabase(
      path,
      onCreate: _onCreate,
      version: 1,
    );
  }

  Future<void> _onCreate(Database db, int version) async {
    await db.execute('''
      CREATE TABLE questions (
        id INTEGER PRIMARY KEY,
        question_text TEXT
      )
    ''');
    await db.execute('''
      CREATE TABLE choices (
        id INTEGER PRIMARY KEY,
        question_id INTEGER,
        choice_text TEXT,
        is_correct INTEGER,
        FOREIGN KEY (question_id) REFERENCES questions (id)
      )
    ''');
    await db.execute('''
      CREATE TABLE user_scores (
        id INTEGER PRIMARY KEY,
        user_id INTEGER,
        score INTEGER
      )
    ''');
  }

  Future<int> insertQuestion(Map<String, dynamic> question) async {
    final db = await database;
    return await db.insert('questions', question);
  }

  Future<void> insertChoice(Map<String, dynamic> choice) async {
    final db = await database;
    await db.insert('choices', choice);
  }

  Future<List<Map<String, dynamic>>> getQuestions() async {
    final db = await database;
    return await db.query('questions');
  }

  Future<List<Map<String, dynamic>>> getChoices(int questionId) async {
    final db = await database;
    return await db.query('choices', where: 'question_id = ?', whereArgs: [questionId]);
  }

  Future<void> insertScore(Map<String, dynamic> score) async {
    final db = await database;
    await db.insert('user_scores', score);
  }

  Future<void> clearData() async{
    final db = await database;
    await db.delete('questions');
    await db.delete('choices');
    await db.delete('user_scores');
  }
}

I can’t display choice texts beside those radio buttons. It displays just as blank, like this:
(https://i.sstatic.net/TMW6paUJ.png)

I tried and checked all data-flow paths and i can’t figure out where the issue may be. ChatGPT isn’t helping