Firestore data model query for document without relationship

Question

What is the best way to structure this data model and to query the data?

I got a Users collection and a Movie collection. I want to create a relationship between those 2 to indicate you've seen your movie. You can easily do that with the following collection:

watch_movies
  - user_id
    - movie_id => true
    - movie_id2 => true
  - user_id2
    - movie_id => true

But I also want to pick up the films that I have not seen yet. How can I best organize this, and which query is useful?

score 1 · Accepted Answer · answered Nov 20 '19 at 19:14

1

Firestore is not well suited for modeling data where a query must find things that don't exist. The way Firestore works is by indexing fields that do exist, and all queries will depend on finding things that exist in those indexes. Indexes simply can't find things that don't exist (because the universe of things that are unknown is extremely large!).

See also:

Consider using another database in tandem with Firestore to satisfy the queries that your app needs.

answered Nov 20 '19 at 19:14

Doug Stevenson

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This is when a value is null, but i wanne the document without a relationship. Can i query all documents but exclude ids? – Jur Dekker Nov 20 '19 at 20:38
No, that sort of query is not supported. – Doug Stevenson Nov 20 '19 at 20:39
So Firestore isn't a option? – Jur Dekker Nov 20 '19 at 20:44
As I said, Firestore is not well suited for this sort of query. You could still make it work if you're willing to filter documents on the client after reading all of them. But there is no native support for this sort of thing. – Doug Stevenson Nov 20 '19 at 20:46
Does it effect the query load time if a take all documents except a limit of 100, when i got like 5000 movies? If not i can do the calculation in the frond-end. – Jur Dekker Nov 20 '19 at 20:52
Yes, the query will take longer if you request more documents. – Doug Stevenson Nov 20 '19 at 21:01
Is are any system i can check the time, before build something? – Jur Dekker Nov 20 '19 at 21:31
Is there a system for making the data structure, except inside firestore? – Jur Dekker Nov 20 '19 at 21:32

Firestore data model query for document without relationship

1 Answers1