How to delete from firebase realtime database?

Question

I am using Firebase realtime database in Android app, and have data like this:

How can i delete the record "Apple" (marked in picture)?

According to the docs, to remove an item you call removeValue() on the reference. But to get the reference i require the child id. Because its a random generated id (-KISNx87aYigsH3ILp0D), how to delete it?

Answer 1

If you don't know the key of the items to remove, you will first need to query the database to determine those keys:

DatabaseReference ref = FirebaseDatabase.getInstance().getReference(); Query applesQuery = ref.child("firebase-test").orderByChild("title").equalTo("Apple");  applesQuery.addListenerForSingleValueEvent(new ValueEventListener() {     @Override     public void onDataChange(DataSnapshot dataSnapshot) {         for (DataSnapshot appleSnapshot: dataSnapshot.getChildren()) {             appleSnapshot.getRef().removeValue();         }     }      @Override     public void onCancelled(DatabaseError databaseError) {         Log.e(TAG, "onCancelled", databaseError.toException());     } }); 

Answer 2

this solved my problem

 mPostReference = FirebaseDatabase.getInstance().getReference()                         .child("quotes").child(mPostKey);                 mPostReference.removeValue();