Firebase Android SearchView by values

Question

I have worked for search about how to search in firebase by vaule and I couldn't have a fully answer so I am asking now ...

I have used this method and I couldn't get the correct result:

I need to search by "Username".

Here's my database:

mSearchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
                @Override
                public boolean onQueryTextSubmit(String query) {
                    return false;
                }

                @Override
                public boolean onQueryTextChange(String newText) {

                    mQuery = mDatabase.orderByChild("Username");


                    return false;
                }
            });

And also I have used:

mSearchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
                @Override
                public boolean onQueryTextSubmit(String query) {
                    return false;
                }

                @Override
                public boolean onQueryTextChange(String newText) {

                    mQuery = mDatabase.orderByChild("Username").equalTo(newText)


                    return false;
                }
            });

but I couldn't so can anyone give me fully correct answer please

---

Thanks AtaerCaner for helping me and also thanks for trying to help me as much as you can, but I still haven't got any result from the Search View so I will give the method that is in my class:

mDatabase.addChildEventListener(new ChildEventListener() {
                @Override
                public void onChildAdded(final DataSnapshot dataSnapshot, String s) {
                    mSearchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
                        @Override
                        public boolean onQueryTextSubmit(String query) {

                            String A = (String) dataSnapshot.child(Post_Key).child("Username").getValue();
                            mQuery = mDatabase.orderByChild(A).equalTo(query);


                            return false;
                        }

                        @Override
                        public boolean onQueryTextChange(String newText) {
                            String A = (String) dataSnapshot.child(Post_Key).child("Username").getValue();
                            mQuery = mDatabase.orderByChild(A).equalTo(newText);
                            return false;
                        }
                    });
                }

So Please check the method if its correct or not ..

Answer 1

Let's think i'm searching Mike. First, bring all users by username with mDatabase.child("Users").orderByChild("Username"). But i want the Mike's datas, so i add .equalTo("Mike"). This returns a query as i say then set an .addListenerForSingleValueEvent to get datas of Mike. The information i want will come as iterable object with one item in this callback. Then cast it to your User modal.

mDatabase.child("Users").orderByChild("Username").equalTo("Mike").addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                  User user = dataSnapshot.getChildren().iterator().next().getValue(User.class);
                }

                @Override
                public void onCancelled(DatabaseError databaseError) {

                }
            });

As far as i see in your code you get the query with mQuery = mDatabase.orderByChild(A).equalTo(newText) but you don't do anything with it.

Maybe this guy can help you https://www.youtube.com/watch?v=3WTQZV5-roY