How can I check if a value exists already in a Firebase data class Android

Question

I want to check if the bus number already exists in the database of Firebase.

Here\'s my sample code. I\'ve been searching for the past days but I can\'t find the rig

Answer 1

Rather than getting whole iterable list of data, you can query for exact entry.

  postRef = FirebaseDatabase.getInstance().getReference().child("BusNumber");

    postRef.orderByChild("busNum").equalTo(busNum)
        .addListenerForSingleValueEvent(new ValueEventListener() {

           @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                if(dataSnapshot.exists()){
                   //bus number exists in Database
            } else {
                //bus number doesn't exists.
            }

            @Override
            public void onCancelled(FirebaseError firebaseError) {

            }
        });