CODEWITHSUNDEEP
androidfirebasefirebase-realtime-database
Samuel
Samuel

Reputation: 640

Firebase get key for the last inserted item

I have a database reference.

houseReference = FirebaseDatabase.getInstance().getReference("House");

I add an item to the db using:

houseReference.push().setValue(house);

Google firebase reference documentation says you can then get the key for the last item using

houseReference.getKey();

However, this returns House. What am I doing wrong?

Upvotes: 2

Views: 2184

Answers (1)

Frank van Puffelen
Frank van Puffelen

Reputation: 598708

Firebase has no concept of "the last key". But each DatabaseReference is a reference to a path in the database, and you get the last key in that path by calling getKey() on it. So if you call houseReference.getKey() you indeed get house, since that is the last key in the path that it refers to.

Now we get to the good stuff though.

When you call push() Firebase generates (in the client) a new unique key, and return a new DatabaseReference that point to that key under the current path. So houseReference.push() returns a new DatabaseReference to the new, unique, child location. And this means that you can call getKey() on this new DatabaseReference to get the last key of that new location.

So:

DatabaseReference newRef = houseReference.push();
System.out.println(newRef.getKey());
newRef.setValue(house);

Upvotes: 6

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