How to get the data from realtime firebase and use it to login

Question

My Firebase Data

I want to get that data and compare it in the text box for my login

Answer 1

try this way

  onTap: () async {
                          
                          final QuerySnapshot result = await FirebaseFirestore
                              .instance
                              .collection(usernameController.text)
                              .get();
                          final List<DocumentSnapshot> documents = result.docs;
                          try {
                            DocumentSnapshot kjnk = documents[1];
                            print(kjnk.id);
                            print(kjnk[kjnk.id]);
                            if (kjnk[kjnk.id] == passwordController.text) {
                              util.showToast("Success");
                              Navigator.pushNamed(context, "/second");
               
                            } else {
                              util.showToast(
                                  "Please Enter the correct Password");
                              Navigator.pop(context);
                            }