如何更新包含数据库中特定值的子节点

String userID = selectedCharacter.getUserID();
String charID = selectedCharacter.getCharID();
Character editedCharacter = new Character(userID, charID, name, hitPoints, armorClass, level, experience, gold);

            databaseRef                     
                    .orderByChild("charID")
                    .equalTo(selectedCharacter.getCharID())
                    .addValueEventListener(new ValueEventListener() {
                        @Override
                        public void onDataChange(DataSnapshot dataSnapshot) {
                            // Translate the character to a map of its data
                            Map<String,Object> updates = editedCharacter.toMap();
                            // Update ONLY the node with charID = editedCharacter.getCharID()
                            databaseRef.updateChildren(updates);
                        }

                        @Override
                        public void onCancelled(DatabaseError databaseError) {
                            throw databaseError.toException();
                        }
                    });
String userID = selectedCharacter.getUserID();