如何在 Android Studio 中从实时 Firebase 中检索特定用户

Question

Hello I am currently doing an appointment chatting application between counsellors and user.

The image is the screenshot of realtime Firebase. https://i.stack.imgur.com/kQG8x.png

So i am trying to do chatting function after the counsellors accepted the booking appointment from the users. However , in my case , it retrieve every counsellors information including counsellors that does not accept the booking. Screenshot of every counsellor appears in my list . I would like to only show "mary" because she is only who accept the appointment booking however according to the image , it shows mary and farah. I would be kindly appreciate if anyone could help me. Thank you.

The following is the code that display every counsellors.

private void displayData(){
    FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
    DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Counsellors");
    reference.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            //mUsers.clear();
            for(DataSnapshot snapshot : dataSnapshot.getChildren()){
                Counsellors counsellor = snapshot.getValue(Counsellors.class);
                if (counsellor!=null && counsellor.getId()!= null && !counsellor.getId().equals(firebaseUser.getUid())){
                    mUsers.add(counsellor);
                }

                userAdapter = new UserAdapter(getContext(),mUsers);
                recyclerView.setAdapter(userAdapter);
            }
        }

        @Override
        public void onCancelled(@NonNull DatabaseError error) {

        }
    });
}

JSON snippets of my realtime Firebase ( Appointment, Counsellors , Users and Chat )

 { "Appointment" : { "-Mo69loW59iUHIMNfLOf" : { "date" : "11/26/21", "idDoctor" : "M8EUBl4vRubeW8iS92HiVIuY4rJ2", "idPatient" : "4WJh1MmoEfN4sqNaJrqbHhNFjxr1", "status" : "Accepted", "time" : "16:06" } }, "Chat" : { "-Mo6A8oY1Kt_ni71IlGN" : { "message" : "helo ", "receiver" : "4WJh1MmoEfN4sqNaJrqbHhNFjxr1", "sender" : "M8EUBl4vRubeW8iS92HiVIuY4rJ2" } }, "Counsellors" : { "M8EUBl4vRubeW8iS92HiVIuY4rJ2" : { "email" : "mary@gmail.com", "id" : "M8EUBl4vRubeW8iS92HiVIuY4rJ2", "name" : "mary", "specialist" : "family mental health" }, "v5FgbL4GuLeOE9ySVe7tgVFEk5D2" : { "email" : "farah24@gmail.com", "id" : "v5FgbL4GuLeOE9ySVe7tgVFEk5D2", "name" : "farah", "specialist" : "anxiety" } }, "Users" : { "4WJh1MmoEfN4sqNaJrqbHhNFjxr1" : { "email" : "jett24@gmail.com", "id" : "4WJh1MmoEfN4sqNaJrqbHhNFjxr1", "matric" : "BI18110293", "name" : "jett" } } }

Answer 1

first of all from my experience with Firebase, I will recommend you to migrate all your data from a real-time database to the Firestore database. Real-time to use only for chatting purposes.

Here is the documentation for the difference between these two databases: RTDB vs Firestore

The second thing is if you need help, please post code snippets to see if there is something wrong with the code. From the text, we cannot help you make fixes in your project.