JAVA

firebase realtime database get key

//firebase reference
DatabaseReference  mRef = FirebaseDatabase.getInstance().getReference();

//set THe_strOX's database contents from the question
mRef.child("clubs").child("-KLpcURDV68BcbAvlPFy").child("dept").setValue("abc");
mRef.child("clubs").child("-KLpcURDV68BcbAvlPFy").child("desc").setValue("xyz");
mRef.child("clubs").child("-KLpcURDV68BcbAvlPFy").child("name").setValue("efg");
mRef.child("clubs").child("-asdasdasddsad").child("dept").setValue("asda");
mRef.child("clubs").child("-asdasdasddsad").child("desc").setValue("asd");
mRef.child("clubs").child("-asdasdasddsad").child("name").setValue("adddd");
//

mRef.child("clubs").addChildEventListener(new ChildEventListener() {
    @Override
    public void onChildAdded(@NonNull DataSnapshot dataSnapshot, String s)
    {
        if (dataSnapshot.exists())
        {
            String pushkey = dataSnapshot.getKey();
            mRef.child("clubs").child(pushkey).addChildEventListener(new ChildEventListener() {
                @Override
                public void onChildAdded(@NonNull DataSnapshot dataSnapshot, String s)
                {
                    if (dataSnapshot.exists())
                    {
                        if (dataSnapshot.getKey().toString().equals("name")) {
                            //edit efg to any desired value
                            if (dataSnapshot.getValue().toString().equals("efg")) {
                                Toast.makeText(MainActivity.this, pushkey, Toast.LENGTH_SHORT).show();
                            }
                        }
                    }
                }
                @Override
                public void onChildChanged(@NonNull DataSnapshot dataSnapshot, String s) { }
                @Override
                public void onChildRemoved(@NonNull DataSnapshot snapshot) { }
                @Override
                public void onChildMoved(@NonNull DataSnapshot snapshot, @androidx.annotation.Nullable String previousChildName) { }
                @Override
                public void onCancelled(@NonNull DatabaseError error) { }
            });
        }
    }
    @Override
    public void onChildChanged(@NonNull DataSnapshot dataSnapshot, String s) { }
    @Override
    public void onChildRemoved(@NonNull DataSnapshot snapshot) { }
    @Override
    public void onChildMoved(@NonNull DataSnapshot snapshot, @androidx.annotation.Nullable String previousChildName) { }
    @Override
    public void onCancelled(@NonNull DatabaseError error) { }
});

firebase realtime database get key

var ref  = database.child("clubs")
val database_listener = object : ValueEventListener {
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            for (ds in dataSnapshot.children) {
                val key = ds.key
           }
        }
     }
   ref.addValueEventListener(database_listener)