Многочисленные поиски в Firebase Flutter

Question

Я пытаюсь создать модуль поиска для своего приложения, посвященного флаттеру, и хочу найти такие предметы, как математика, физика и т. Д. c. Но проблема в том, что я добавил 3 предмета для каждого учителя, и учитель мог бы добавить такой предмет, как физика, в предмет 1 или в предмет 2 или в предмет 3, поэтому я понятия не имею, как искать во всех них и отображать всех учителей, которые преподают физику , Есть ли сложный запрос, потому что я не смог его найти. Я был бы очень признателен за любую помощь. Вот мой код до сих пор.

import 'package:etutor/ReusableMaterial/Constants.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:getflutter/components/avatar/gf_avatar.dart';
import 'package:getflutter/shape/gf_avatar_shape.dart';
import 'package:line_icons/line_icons.dart';

class Search extends StatefulWidget {
  @override
  _SearchState createState() => _SearchState();
}

class _SearchState extends State<Search> with SingleTickerProviderStateMixin {
  Firestore fireStore = Firestore.instance;

  AnimationController _animationController;
  final TextEditingController _textController = new TextEditingController();
  bool isPlaying = false;
  String lists;
  double value = 40;

  var enableBorder = Color(0xFFdcd6f7);
  var focusBorder = Color(0xFFa6b1e1);
  var actualEnableBorder = Color(0xFFdcd6f7);
  var actualFocusBorder = Color(0xFFa6b1e1);
  @override
  void initState() {
    super.initState();

    _animationController =
        AnimationController(vsync: this, duration: Duration(milliseconds: 300));
  }

  Future<QuerySnapshot> getAllDocuments() {
    return fireStore.collection('userData').getDocuments();
  }

  @override
  void dispose() {
    super.dispose();
    _animationController.dispose();
  }

  void _handleOnPressed() {
    setState(() {
      isPlaying = !isPlaying;
      isPlaying
          ? _animationController.forward()
          : _animationController.reverse();
      isPlaying ? value = 300 : value = 40;
      isPlaying
          ? focusBorder = actualFocusBorder
          : focusBorder = Colors.transparent;
      isPlaying
          ? enableBorder = actualEnableBorder
          : enableBorder = Colors.transparent;
      _textController.clear();
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Column(
          children: <Widget>[
            Center(child: Text('Search', style: kHeadingStyle)),
            SizedBox(height: 50),
            Row(
              mainAxisAlignment: MainAxisAlignment.end,
              children: <Widget>[
                Padding(
                  padding: const EdgeInsets.only(right: 45.0),
                  child: AnimatedContainer(
                    curve: Curves.easeInCirc,
                    decoration: BoxDecoration(
                      borderRadius: BorderRadius.circular(10),
                      color: Colors.transparent,
//                      color: Color(0xFFeaeaea),
                    ),
                    height: 50,
                    width: value,
                    duration: Duration(seconds: 1),
                    child: TextFormField(
                      controller: _textController,
                      decoration: InputDecoration(
                        suffixIcon: IconButton(
                            icon: AnimatedIcon(
                                color: kBlueColor,
                                icon: AnimatedIcons.ellipsis_search,
                                size: 30,
                                progress: _animationController),
                            onPressed: () {
                              _handleOnPressed();
                            }),
                        hintText: 'Search...',
                        enabledBorder: OutlineInputBorder(
                          borderSide:
                              BorderSide(color: enableBorder, width: 1.0),
                          borderRadius: BorderRadius.all(Radius.circular(10.0)),
                        ),
                        focusedBorder: OutlineInputBorder(
                          borderSide:
                              BorderSide(color: focusBorder, width: 2.0),
                          borderRadius: BorderRadius.all(Radius.circular(10.0)),
                        ),
                      ),
                      keyboardType: TextInputType.text,
                      onChanged: (value) {},
                    ),
                  ),
                ),
              ],
            ),
            SizedBox(height: 30),
            StreamBuilder<QuerySnapshot>(
              stream: fireStore
                  .collection('userData')
                  .where('subject1', isEqualTo: 'Mathematics')
                  .snapshots(),
              builder: (context, snapshot) {
                if (snapshot.hasData) {
                  final doc = snapshot.data.documents;
                  List<SearchMaterial> newTemp = [];
                  for (var t in doc) {
                    final userName = t.data['Name'];
                    final userEmail = t.data['Email'];
                    final userImageURL = t.data['imageURl'];
                    final subject1 = t.data['subject1'];
                    final subject2 = t.data['subject2'];
                    final subject3 = t.data['subject3'];
                    final rating = t.data['rating'];
                    final newTemp3 = SearchMaterial(
                      userName: userName,
                      email: userEmail,
                      imageUrl: userImageURL,
                      subject1: subject1,
                      subject2: subject2,
                      subject3: subject3,
                      rating: rating,
                    );
                    newTemp.add(newTemp3);
                  }
                  return Expanded(
                    child: ListView(
//                      reverse: true,
                      children: newTemp,
                    ),
                  );
                }
                return Center(child: Image.asset('images/book.gif'));
              },
            )
          ],
        ),
      ),
    );
  }
}

class SearchMaterial extends StatelessWidget {
  final String userName;
  final String email;
  final String imageUrl;
  final String subject1;
  final String subject2;
  final String subject3;
  final String rating;

  const SearchMaterial(
      {this.userName,
      this.email,
      this.imageUrl,
      this.subject1,
      this.subject2,
      this.subject3,
      this.rating});

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(left: 40.0, right: 40, bottom: 30),
      child: Container(
        height: 115,
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(10),
          boxShadow: [
            BoxShadow(
              color: Color.fromRGBO(84, 104, 255, .15),
              blurRadius: 10,
              offset: Offset(1, 5),
            )
          ],
        ),
        child: Stack(
          children: <Widget>[
            Align(
              alignment: Alignment(-1, 0),
              child: Padding(
                padding: const EdgeInsets.all(8.0),
                child: GFAvatar(
                  backgroundColor: Colors.white,
                  size: 60,
                  shape: GFAvatarShape.standard,
                  backgroundImage: NetworkImage(
                    '$imageUrl',
                    scale: 1.0,
                  ),
                ),
              ),
            ),
            Align(
              alignment: Alignment(0.95, -.85),
              child: Container(
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: <Widget>[
                    Icon(LineIcons.star),
                    Text('$rating'),
                  ],
                ),
                height: 25,
                width: 70,
                decoration: BoxDecoration(
                  color: Color(0xFFffd868),
                  borderRadius: BorderRadius.circular(15),
                ),
              ),
            ),
            Container(
                child: Padding(
              padding: EdgeInsets.only(left: 112.0, top: 30),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: <Widget>[
                  Text('$userName'),
                  SizedBox(height: 15),
                  Text('$subject1'),
                  Text('$subject2'),
                  Text('$subject3'),
                ],
              ),
            ))
          ],
        ),
      ),
    );
  }
}