About Firebase real time database - flutter

Question

I am working on Firebase real time databases in Flutter. I am storing user information and their corresponding data in database. My code is given below:
//User Auth Class
class UserAuth{
final String id;
final String email;
final String token;
UserAuth({#required this.id, #required this.email, #required this.token});
}
//User Details Class for storing data of corresponding user
class UserDetails{
final String userDetailsId;
final String name;
final String email;
UserDetails({#required this.userDetailsId,#required this.name, #required this.email});
}
//I am using this code to add userDetails in database.
List<UserDetails> _detailsList = [];
UserDetails _details;
Future<bool> addUserDetails(String username, String email) async {
_isLoading = true;
notifyListeners();
final Map<String, dynamic> userDetails = {
'username': username,
'email': email,
};
try {
final http.Response response = await http.post(
'https://intro-to-firebase-711d4.firebaseio.com/Users.json',
body: json.encode(userDetails));
if (response.statusCode != 200 && response.statusCode != 201) {
_isLoading = false;
notifyListeners();
return false;
}
final Map<String, dynamic> responseData = json.decode(response.body);
_details = UserDetails(
userDetailsId: responseData['name'], name: username, email: email);
_detailsList.add(_details);
_isLoading = false;
notifyListeners();
return true;
} catch (error) {
_isLoading = false;
notifyListeners();
return false;
}
}
Now I want to get the following highlighted ids of the user so how to fetch it. I am using scoped model as a state management in Flutter.

Answer 1

I did it with javascript so far but in the documentation it seems not taht different for flutter:
private void writeNewUser(String userId, String name, String email) {
User user = new User(name, email);
mDatabase.child("users").child(userId).setValue(user);
}
https://firebase.google.com/docs/database/android/read-and-write?authuser=0
This is the example shown in the docs. with .child('users') you can get the right section .child(userId) gives you access to the values.
All you have to do now is defining the variable userId
flutter
you can achieve this as follows
stream: FirebaseDatabase.instance
.reference()
.child('users')
.equalTo(userId)
.onValue,