Google App Engine ndb equivalent for modelname_set (backreference property)

Question

Is there an equivalent for modelname_set (a back-referenced property) in Google App Engine\'s NDB?

In the old DB a Model entity had described the back-r

Answer 1

There is no direct back-reference properties in NDB because NDB doesn't quite use the same paradigm as the original datastore client. You would use a KeyProperty for your forward reference and then use a query for everything that has that KeyProperty set for your back reference.

class Comment(ndb.Model)
    source = ndb.KeyProperty()

qry = Comment.query().filter(source=ndb.Key('Source', 'Sandy'))