[push] Firebase: how to generate a unique numeric ID for key?

I need numeric IDs for human readability. How do I get it in Firebase?

I want numeric ID for keys, e.g. "000000001", "000000002","00000003","00000004".

The reason I need it is because these IDs will become the permanent object ID both online and offline. I want users to be able to browse that object page by just entering URL "/objects/00000001" without efforts.

I am asking here, because I want to know if this can be done without using .priority, sub-properties, etc. I guess set method can do it somehow. If it is not possible, just tell me no, I can accept that answer.

As explained above, you can use the Firebase default push id.

If you want something numeric you can do something based on the timestamp to avoid collisions

f.e. something based on date,hour,second,ms, and some random int at the end

01612061353136799031

Which translates to:

016-12-06 13:53:13:679 9031

It all depends on the precision you need (social security numbers do the same with some random characters at the end of the date). Like how many transactions will be expected during the day, hour or second. You may want to lower precision to favor ease of typing.

You can also do a transaction that increments the number id, and on success you will have a unique consecutive number for that user. These can be done on the client or server side.

(https://firebase.google.com/docs/database/android/read-and-write)

https://firebase.google.com/docs/firestore/manage-data/transactions

Use transactions and keep a number in the database somewhere that you can increase by one. This way you can get a nice numeric and simple id.

Adding to the @htafoya answer. The code snippet will be

const getTimeEpoch = () => {
    return new Date().getTime().toString();                             
}

As the docs say, this can be achieved just by using set instead if push.

As the docs say, it is not recommended (due to possible overwrite by other user at the "same" time).

But in some cases it's helpful to have control over the feed's content including keys.

As an example of webapp in js, 193 being your id generated elsewhere, simply:

 firebase.initializeApp(firebaseConfig);
  var data={
      "name":"Prague"
  };
  firebase.database().ref().child('areas').child("193").set(data);

This will overwrite any area labeled 193 or create one if it's not existing yet.