Firestore query by Object Key

Question

I have a series of nested objects in a collection in firestore, that have a key of a UID. I want to query all documents that relate to a user, by checking if their UID is the object key (basically if it exists). This is the model in firestore:

and this is how I am currently trying to return the documents:

  getAllTenancyOffersByUserId() {
    return this.afs.collection('collection_name', ref =>
      ref.where(`application.members.${this._auth.currentUserId}`, '==', !null),
    );
  }

but this returns nothing. I understand that I could just query by that status, however it is constantly updating so will cause problems

Answer 1

The following should do the trick:

  getAllTenancyOffersByUserId() {
    return this.afs.collection('members', ref =>
      ref.where(firebase.firestore.FieldPath.documentId(), '==', `${this._auth.currentUserId}`)
    );
  }

See the corresponding doc: https://firebase.google.com/docs/reference/js/firebase.firestore.FieldPath#.documentId

Answer 2

Actually, what you could do is to filter by any string field that you have in the object like this:

.collection("collectionName")
.where("mapArray.map.stringField", ">", "''")

the important part here is the string field being; ">", "''"

Answer 3

I believe it is not possible to query whether a object exists or not. I think your idea of querying a field inside your object may be the best bet.

What you could try is querying the date_modified field for anything greater than 1900.

getAllTenancyOffersByUserId() {
  return this.afs.collection('collection_name', ref =>
    ref.where(`
      application.members.${this._auth.currentUserId}.date_modified`, 
      '>=',
      new Date('1900-01-01')
    ),
  );
}