Why the documents (that have further sub collection) size is 0 when you call .collection("collName"). get()?

Question

I have a similar problem as this question question, but no one has answered yet. I have a collection that has documents and those documents have further collections. When I try to get these documents I receive 0 documents. database image

Code

db.collection("teachers").document("irfany").collection("OpenAssignments").
        get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<QuerySnapshot> task) {
        if (task.isSuccessful()) {
            Log.d("getdocumentSize", task.getResult().size() + " => ");

            for (QueryDocumentSnapshot document : task.getResult()) {

            }
        } else {
            Log.d("Error", "Error getting documents: ", task.getException());
        }
    }
});

Output D/getdocumentSize: 0 =>

The document seems to be empty ie. doesn't exist (but maybe has a sub-collection). Try adding a field in it and it should so up. — Dharmaraj, Aug 20 '22 at 07:22
Thanks for your reply but If you look into the image provided inquestion "Database Image "there is the document in it. — irfan yaqub, Aug 20 '22 at 07:28
The document ID is italic that indicates it's empty/inexistent. — Dharmaraj, Aug 20 '22 at 07:29
You are absolutely right, i have created another document and i fetched the document. Thanks — irfan yaqub, Aug 20 '22 at 07:40
Why did you delete this [question](https://stackoverflow.com/questions/73426102/why-creating-multiple-documents-at-same-time-with-subcollection-appear-as-italic)? — Alex Mamo, Aug 22 '22 at 08:12

score 2 · Accepted Answer · answered Aug 20 '22 at 09:03

The Math 101 document in the provided screenshot does not exist (as indicated by the italic document ID) but there's a sub collection assignmentData in it. If you still want to query all document in OpenAssignments then it'll be best to add a field in the document to actually create it.

If your goal is to query assignmentData documents of all OpenAssignments then you can use a Collection Group query instead.

Also checkout: Firestore query returns no documents even though they are shown in the console in italics

In short, it's just a holder for the sub-collection that exists under it. — Alex Mamo, Aug 20 '22 at 09:39

Why the documents (that have further sub collection) size is 0 when you call .collection("collName"). get()?

1 Answers1

Related