How to show all login users data to admin using Firebase?

Question

I want to show data of all users from firebase without users id in firebase RecyclerView. How can it be possible? I am working on my first firebase project and I am new in Firebase. Here is my code but it shows just login user data.

java

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_dash_board);

        recyclerView=findViewById(R.id.recycler);

        mAuth=FirebaseAuth.getInstance();
        FirebaseUser mUser=mAuth.getCurrentUser();
        final String uId=mUser.getUid();
        mDatabase= FirebaseDatabase.getInstance().getReference().child("UserName").child(uId);
        mDatabase.keepSynced(true);

        LinearLayoutManager linearLayoutManager=new LinearLayoutManager(this);
        linearLayoutManager.setReverseLayout(true);
        linearLayoutManager.setStackFromEnd(true);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(linearLayoutManager);
    }

    @Override
    protected void onStart() {
        super.onStart();

        FirebaseRecyclerAdapter<Data, DashBoard.MyViewHoler>adapter= new FirebaseRecyclerAdapter<Data, MyViewHoler>(Data.class, R.layout.item_data, DashBoard.MyViewHoler.class,mDatabase) {

            @Override
            protected void populateViewHolder(MyViewHoler myViewHoler, Data data, int i) {
                myViewHoler.setName(data.getNamee());
                myViewHoler.setCity(data.getCityy());
                myViewHoler.setCell(data.getCelll());
                myViewHoler.setFund(data.getFundd());

            }
        };

        recyclerView.setAdapter(adapter);
     }

firebase

What's wrong with this code? Please also add your database structure as a JSON file or at least a screenshot. — Alex Mamo, Feb 06 '20 at 11:16
not wrong with my code i just want to see you is there any problem which not show all data without login — Waqar Ahmed, Feb 06 '20 at 11:26

score 0 · Answer 1 · answered Feb 06 '20 at 11:34

To solve this, please use the following lines of code:

String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference uidRef = rootRef.child("UserName").child(uid);
ValueEventListener valueEventListener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for(DataSnapshot ds : dataSnapshot.getChildren()) {
            String name = ds.child("name").getValue(String.class);
            Log.d(TAG, name);
        }
    }

    @Override
    public void onCancelled(@NonNull DatabaseError databaseError) {
        Log.d(TAG, databaseError.getMessage()); //Don't ignore errors!
    }
};
uidRef.addListenerForSingleValueEvent(valueEventListener);

The result in the logcat will be:

Azar khan
khan
...

If you want to use Firebase-UI library to display your element in a list, please see my answer from the following post:

How can I retrieve data from Firebase to my adapter

This code just for login user. I mean to say that an admin can show all users data which users add in firebase. — Waqar Ahmed, Feb 06 '20 at 11:40
I'm afraid I did not understand. Can you please be more specific? — Alex Mamo, Feb 06 '20 at 11:44
I am making an app in which admin and users log in and after login user can add detail of fund rzr and admin can show the user name and total fund of user which donors give the user. — Waqar Ahmed, Feb 06 '20 at 12:02
I cant show all these data to admin. How can i do.? I have no idea — Waqar Ahmed, Feb 06 '20 at 12:12

Md. Asaduzzaman · Answer 2 · 2020-02-06T12:19:27.577

0

You should reference your database to UserName and then iterate through each user to get data. Check below:

DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference().child("UserName");
databaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
        for(DataSnapshot userSnapshot: dataSnapshot.getChildren()) {
            for(DataSnapshot childSnapshot: userSnapshot.getChildren()) {
                Data data = childSnapshot.getValue(Data.class);


            }
        }
    }

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

    }
});

edited Feb 06 '20 at 12:19

answered Feb 06 '20 at 11:57

Md. Asaduzzaman

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NullPointerException: Attempt to invoke virtual method 'com.google.firebase.database.ChildEventListener com.google.firebase.database.Query.addChildEventListener(com.google.firebase.database.ChildEventListener)' on a null object reference – Waqar Ahmed Feb 06 '20 at 12:11
But I have initialize `mDatabase`, Probably the error from other code. Can you try directly with `FirebaseDatabase.getInstance().getReference().child("UserName").addListenerForSingleValueEvent...` and check – Md. Asaduzzaman Feb 06 '20 at 12:15
Probably it conflicts with your variable, I have change the name. Can you try with updated code and let me know? – Md. Asaduzzaman Feb 06 '20 at 12:20
@waqar-ahmed, Have you checked the updated answer? Is this help you? – Md. Asaduzzaman Feb 11 '20 at 07:05

How to show all login users data to admin using Firebase?

2 Answers2