javascript - Firestore collection group query on documentId

Question

In my scenario a user can "like" the profile of another user. As a result I have a subcollection called "likedBy" for each user, where I create a document for a specific user, e.g.:

users(col) -> User A(doc) -> likedBy(col) -> User B (doc), User C (doc)

So in the rare scenario of a user being deleted, I want to delete all the likes issues by that user.

I am just not sure if this is even possible (a workaround could be to just save the userId again in said document and query for that).

What I am basically looking for is something like this:

db.collectionGroup('likedBy').where(firebase.firestore.FieldPath.documentId(), '==', "User A").get();

The problem is, that I can not create an index for the documentId in the Firestore console.

Answer 1

Waitting for answers