Angular Firestore | how to get array not contain

Question

I'm using Angular Firestore in my app, and I'm having a problem to write a query that will return all of the objects I'm needed

In the following example, I get all the fruits that got that user id in their eat_by array

this.asf.collection('fruits', ref => ref.where('eat_by', 'array-contains', userId)).valueChanges();

and its working great

But the problem I'm having is doing the opposite thing; I'm trying to get the fruits that don't have that userId in there eat by the array. Like $nin in mongo.

I need that the field value is not in the specified array operator

did you handle with that thing before ?

how did you resolve it ?

there is any good workaround ?

Thank you

Answer 1

firebaser here

There is no "array does not contain" operation is Cloud Firestore at the moment.

I highly recommend reading Doug's answer here, as it explains why this operation is not supported. Unfortunately the workaround proposed there, won't work for "array does not contain" operations.