Remove Specific value From Firebase Database

Question

I want to Delete Specific value from Firebase Database following is Database which i have stored

Now, I want to Delete Fol

Answer 1

Try this code. Hopefully this will help you Thanks

database.getReference().child("Groups").child(groupItem.getGroupkey()).child("members").child(groupMember.getKey()).removeValue().addOnSuccessListener(new OnSuccessListener<Void>() {
                                   @Override
                                   public void onSuccess(Void aVoid) {
                                       new CustomMessage(GroupDetailsActivity.this, "Successfully deleted");
                                   }
                               }).addOnFailureListener(new OnFailureListener() {
                                   @Override
                                   public void onFailure(@NonNull Exception e) {
                                       Customlog.showlogD("ERROR_MSG",e.getMessage());
                                   }
                               });

Database structure: https://i.stack.imgur.com/Lw3Ia.png

Answer 2

Well Thanks to all, After Modification with lots of answer and query.. This is what worked with me.

mReference.child("demo").orderByChild("fname").equalTo("John").addChildEventListener(new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {
            mReference.child("demo").child(dataSnapshot.getKey()).setValue(null);

            //also work
            //dataSnapshot.getRef().setValue(null);  
        }

        @Override
        public void onChildChanged(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onChildRemoved(DataSnapshot dataSnapshot) {

        }

        @Override
        public void onChildMoved(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

Answer 3

hi try using this code,

    mReference.child("demo").orderByChild("fname").equalTo("John").addListenerForSingleValueEvent(
            new ValueEventListener() {
                @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            mReference.child("demo").child(dataSnapshot.getKey()).setValue(null);
        }

       @Override
         public void onCancelled(DatabaseError databaseError) {
              Log.w("TodoApp", "getUser:onCancelled", databaseError.toException());
         }
});

Answer 4

Instead of using addListenerForSingleValueEventtry using addChildEventListener as below,

Query queryRef = mReference.child("demo").orderByChild("fname").equalTo("John");

queryRef.addChildEventListener(new ChildEventListener() {
    @Override
    public void onChildAdded(DataSnapshot snapshot, String previousChild) {
      snapshot.getRef().setValue(null);
    }
});

Answer 5

You can try it:

mReference.child("demo").orderByChild("fname").equalTo("John").addListenerForSingleValueEvent(
                new ValueEventListener() {
                    @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                 dataSnapshot.getRef().setValue(null);
            }


           @Override
             public void onCancelled(DatabaseError databaseError) {
                  Log.w("TodoApp", "getUser:onCancelled", databaseError.toException());
             }
   });