Firebase - generate child with children for a registered user

Question

I want to add in Firebase multiple data when a user registers to my app, including a node "Scores" with some children, but I don't know how to add it.

Firebase Database:

"Users" : {
   "L89LA3099j-VAhi5Y5P" : {
      "Admin" : false,
      "Email" : "[email protected]",
      "Nickname" : "Anonymous",
      "Picture" : "https://firebasestorage.googleapis.com/v0/b/cul...",
      "Scores" : {
         "Arts" : 0,
         "Classical music" : 0,
         "Literature" : 0
      }
   }
}

And here is the code in Android Studio:

 FirebaseAuth.getInstance().createUserWithEmailAndPassword(email, password).addOnCompleteListener(UserRegistration.this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {

                    if (!task.isSuccessful()) {
                        Toast.makeText(UserRegistration.this, "Invalid email or already existed email!", Toast.LENGTH_SHORT).show();
                    } else {
                        DatabaseReference usersRef = FirebaseDatabase.getInstance().getReference().child("Users");
                        HashMap<String, Object> user_data = new HashMap<>();
                        user_data.put("Admin", false);
                        user_data.put("Email", email); // I got it correctly from EditText
                        user_data.put("Picture", "https://firebasestorage.googleapis.com/v0/b/cul...");
                        user_data.put("Nickname", "Anonymous");
                        usersRef.child("Users").push().setValue(user_data);

                        DatabaseReference scores_ref = usersRef.child("Scores"); // I guess it's wrong to do it like this
                        HashMap<String, Integer> user_scores = new HashMap<>();
                        user_scores.put("Arts", 0);
                        user_scores.put("Classical music", 0);
                        user_scores.put("Literature", 0);

                        // and now how to add Scores node inside the created user?

Answer 1

If you want to add Scores under a user then try the following:

First use the userid and not the push()

FirebaseUser mCurrentUser= task.getResult().getUser();
String userid=mCurrentUser.getUid();

then change this:

usersRef.child("Users").push().setValue(user_data);

to this:

usersRef.child(userid).setValue(user_data);
DatabaseReference scores_ref =usersRef.child(userid).child("Scores"); 
scores_ref.child("Arts").setValue(0);
scores_ref.child("Classical music").setValue(0);
scores_ref.child("Literature").setValue(0);

userRef points to child Users

this line usersRef.child(userid).setValue(user_data);

will create the following:

Users
  userid
     Admin : false
     Email : [email protected]
     Nickname" : Anonymous
     Picture" : https://firebasestorage.googleapis.com/v0/b/cul...

Then this line DatabaseReference scores_ref =usersRef.child(userid).child("Scores");

will pass through node Users, then node userid and it will add child Scores and it's children. All will be under the current userid.