Firebase Realtime数据库获取push（）参考

Question

This is how I save my Events in my app:

FirebaseDatabase.getInstance().getReference().child("events").push().setValue(ev);

Now I would like each event to have its own chat room where users can send messages to each other. However, I need to know the reference to the event so I can add the chat room. I don't want to change the Event object to have this property. How do I do that?

databaseRef = FirebaseDatabase.getInstance().getReference().child("events").child(?);

Answer 1

You can reference the pushed event using DatabaseReference#getKey() , so to retrieve the newly added event, call:

String eventId = FirebaseDatabase.getInstance().getReference().child("events").push()
                                                                              .getKey()

Then you can do:

FirebaseDatabase.getInstance().getReference().child("events").child(eventId)...