Cannot use the "not equal" operator when querying for a collection in AngularFire

Question

I am trying to pull a collection from Firebase that is not associated to the user. So far, I've successfully queried for the user's collection, but I can't seem to get the collection that is not associated with the user using the != operator.

Here's my code:

  // Does not work!
  eventCollection: AngularFirestoreCollection<Event> = this.angularFirestore.collection("events", ref =>
    ref.where("uid", "!=", this.firebaseAuth.auth.currentUser.uid)
  );
  eventCollection$: Observable<Event[]> = this.eventCollection.valueChanges();

  // Works!
  myCollection: AngularFirestoreCollection<Event> = this.angularFirestore.collection("events", ref =>
    ref.where("uid", "==", this.firebaseAuth.auth.currentUser.uid)
  );
  myCollection$: Observable<Event[]> = this.myCollection.valueChanges();

The error that's thrown is:

ERROR in src/app/event/events.service.ts(35,22): error TS2345: Argument of type '"!"' is not assignable to parameter of type 'WhereFilterOp'.

I tried looking for a logical operator that corresponds to !=, but can't seem to find it.

Any help would be greatly appreciated!

score 3 · Accepted Answer · answered Aug 16 '18 at 16:53

3

According to Firestore doc:

Queries with a != clause. In this case, you should split the query into a greater-than query and a less-than query. For example, although the query clause where("age", "!=", "30") is not supported, you can get the same result set by combining two queries, one with the clause where("age", "<", "30") and one with the clause where("age", ">", 30).

So you must compare both '<' and '>' condition

eventCollection: AngularFirestoreCollection<Event> = 
  this.angularFirestore.collection("events", ref =>
    ref.where("uid", ">", this.firebaseAuth.auth.currentUser.uid)
       .where("uid", "<", this.firebaseAuth.auth.currentUser.uid)
  );

answered Aug 16 '18 at 16:53

hgiasac

2,183
16
14

Thank you so much! It worked! – memo khoury Aug 16 '18 at 17:21
5

How does this work when comparing `String` type auth uids? – Jantzilla Oct 25 '18 at 08:01
2

does this not do && instead of || ? – ebg11 Nov 23 '19 at 11:32
@ebg11 i'm thinking the same. Has anyone tried this? In my understanding this produces an empty result. – Martin Cremer Jun 29 '20 at 15:31
tried it, it doesnt work. How can this be the right answer. – Martin Cremer Jun 29 '20 at 15:46

score 1 · Answer 2 · answered Aug 16 '18 at 16:49

It looks like there is no != operator. I'm not familiar with Firebase, but perhaps you could do separate queries for < and > and combine the results? Or since you also want the equal results, just do one query without the where and separate the equal and unequal results yourself?

Cannot use the "not equal" operator when querying for a collection in AngularFire

2 Answers2