Firestore - get the parent document of a subcollection

Question

I'm working on an app that uses a firestore database with the following hierarchy: parent_collection: parent_document: subcollection: child_document{ string name} using collectionGroup I've been able to query subcollection for documents with a certain name, but I don't know how to get the parent_document

 db.collectionGroup("subcollection").whereEqualTo("name", searchText).get()                 .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {                     @Override                     public void onComplete(@NonNull Task<QuerySnapshot> task) {                         if(task.isSuccessful()){                           //here I want to get the parent id of all results                         }                     }                 }); 

What is the best way to achieve that?

Answer 1

The QuerySnapshot points to a number of QueryDocumentSnapshot instances.

From a QueryDocumentSnapshot, you can get the collection it's from with:

snapshot.getRef().getParent() 

And then the parent DocumentReference is:

snapshot.getRef().getParent().getParent() 

So to get a subscollection of the parent document with:

snapshot.getRef().getParent().getParent().collection("name_of_subcollection") 

Yes, I agree... that could've been a bit more readable. :)