Mutual Model relations

Got this baby today. DuplicatePropertyError ModelName already has property ModelName_set. Caused by this code: class Address(BaseModel): name = db.StringProperty() addressLine1 = db.StringProperty() addressLine2 = db.StringProperty() zip = db.StringProperty() city = db.StringProperty() country = db.StringProperty() class SantaRelation(BaseModel): code = db.StringProperty() giver = db.ReferenceProperty(Address) receiver = db.ReferenceProperty(Address) isReceived = db.BooleanProperty() creationDate = db.DateTimeProperty(auto_now_add=True) image = db.Blob() note = db.StringProperty() The solution is to define the underlying collection name via the collection_name argument to the ReferenceProperty constructor, as it will default to "modelname_set" otherwise, causing the DuplicatePropertyError.

    giver = db.ReferenceProperty(Address, collection_name='address_giver_set')
    receiver = db.ReferenceProperty(Address, collection_name='address_receiver_set')

Presto!