List subcollections of a document with AngularFire in Firestore

Question

Data structure example

I have a simple data structure, collection of wallets and collection of transactions in each wallet, what a simple way to get all transactions from each wallet using angularfire2?

Answer 1

There is currently no way to query across multiple collections with the Cloud Firestore SDK. If you want to access the data from multiple collections, you will have to load the data from each collection and then handle the rest in your application code.

Alternatively you could keep all transactions in a single top-level collection and associate them with their wallet through a field in the document.

A final option is to keep the transactions in both places: both in a global list and for each user. While this doubles the amount of data you store, it'll likely make lookups easier, and faster.