如何使用 Z047B10EEE763AFB6164E077CF1CC268Z 将文档子集合与文档 JSON map 一起使用 Z035489FF8D0924748149

Question

I'm trying to get all the documents in the "businesses" collection from Firebase together with their sub-collections.

The problem is when I do the query to Firebase like this:

Stream<List<Business>> getBusinesses() {
return _db.collection('businesses').snapshots().map((snapshot) => snapshot
    .docs
    .map((document) => Business.fromJson(document.data()))
    .toList());

}

, the sub-collections aren't passed with the JSON object document.data() , so in my code, the Business object isn't fully completed, which means there are empty fields (Appointments, ServiceProviders, Services), instead of getting the data from the sub-collections.

So hopefully I've explained the problem well, my question is how can I fetch all the document data including its sub-collections, and parse it to a Business Object?

Thanks.

Answer 1

What seems to be "the problem" is actually the point of Firestore: Keeping documents shallow so you can only get the data you need. It's then up to you to structure your data the way it will likely be used in the future.

Mind you, subcollections are not fields.

What you can do here, is add a query that fetches the documents in the subcollections (Appointments, ServiceProviders, Services), for each business. You would get the business document Id to use for the query.

It would typically look something like:

_db.collection('businesses').document(documentId).collection('Appointments')

Mind you, this is potentially too much data. It might be better to fetch the docs in those subcollections only when needed/requested by the user.