Firestore get data from a random generated document

Question

I have a firestore like this

ppl (collection)
   1 (document)
    school(collection)
        jhdsfjhdsgfjh (random generated document)
               jobname(collection field)
                  teacher:1 (collection field1)
                  advisor:2 (collection field2)

I want to extract teacher and advisor in a JSON file but I am not able to

my code so far:

 doc_ref = db.collection(u'ppl').document('1')
 doc = doc_ref.get
 docuout =  doc_ref.collection('school').document().collection().stream()

 document_output=docuout.to_dict()

it's returning an empty document_output. Any idea how to fix it ?

score 0 · Answer 1 · answered Oct 12 '21 at 14:18

0

Every time you call document() without parameters, it generates a reference to a new/non-existing document. So you're trying to stream a subcollection of a non-existing document, which explains why you don't get any results.

If you want to get the subcollection for a specific document, specify the ID for that document in the call to document("id here") as shown in the docs on getting a document. If you don't know the ID of the document, you will need to know something else that uniquely identifies the document and can then use a query to find the document.

If you want to get a random document from the school collection, have a look at Dan's excellent answer here: Firestore: How to get random documents in a collection

answered Oct 12 '21 at 14:18

Frank van Puffelen

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Is there anyway to find the value of the random document id ? I dont know the ID of it because it was automatically generated – JM17 Oct 13 '21 at 12:05
If you know something else that identifies the document, you can find the document ID using a query. See the link I posted in my answer for the docs on that. – Frank van Puffelen Oct 13 '21 at 14:23
Hey @J1701. Any updates there? – Frank van Puffelen Oct 19 '21 at 00:03

Firestore get data from a random generated document

1 Answers1