How to search if a username exist in the given firebase database?

Question

{
 users:
  {
    apple:
     {
       username :  apple
       email    :  apple@xy.com
       uid      :  tyutyutyu
     }
    mango:
     {
       username :  man         


        

Answer 1

You may try this.

                final String userName = unameEditText.getText().toString();
                databaseReference.child("users").orderByChild("username").equalTo(userName).addListenerForSingleValueEvent(
                        new ValueEventListener() {

                            @Override
                            public void onDataChange(DataSnapshot dataSnapshot) {

                                Log.i(Constants.TAG, "dataSnapshot value = " + dataSnapshot.getValue());

                                if (dataSnapshot.exists()) {

                                    // User Exists
                                    // Do your stuff here if user already exists
                                    Toast.makeText(getApplicationContext(), "Username already exists. Please try other username.", Toast.LENGTH_SHORT).show();

                                } else {

                                    // User Not Yet Exists
                                    // Do your stuff here if user not yet exists
                                }
                            }
                            @Override
                            public void onCancelled (DatabaseError databaseError){

                            }
                        }

                );