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Django: How do you access a model's instance from inside a manager?

class SupercalifragilisticexpialidociousManager(models.Manager):
    # Sorry, I'm sick of Foo and Spam for now.
    def get_query_set(self, account=None):
        return super(SupercalifragilisticexpialidociousManager,
                     self).get_query_set().filter(uncle开发者_StackOverflow=model_thats_using_this_manager_instance.uncle)

The magic I'm looking for is the "uncle=model_thats_using_this_manager_instance.uncle". It seems like I should be able to do this somehow. I know I could say self.model to get the model, but how to get the instance?


It doesn't make sense to ask for an instance when you're using a manager. Managers are class-level attributes - if you try and do foo.objects.all() where foo is an instance of Supercalifragilisticexpialidocious, you will explicitly get an error:

AttributeError: Manager isn't accessible via Supercalifragilisticexpialidocious instances


As far as I know, you cannot access the model from inside a manager. It doesn't make sense as managers operate on the whole table.

You should do something like this in the model:

class Model(models.Model):
    # some attributes here
    def getAllRelativesWithSameUncle(self):
        return Model.objects.filter(uncle = self.uncle)

or in the manager:

class SupercalifragilisticexpialidociousManager(models.Manager):
    def getSelfRelativesFor(self, model):
        return self.get_queryset().filter(uncle=model)


In methods like object.related_name.create() under the hood the Djangos sends a hint argument:

class UserQuerySet(QuerySet):
    def create(self, *args, **kwargs):
        print(self._hints)
        # >>> {'instance': <User: random-user>}
        print(self._hints.get('instance'))
        # >>> <User: random-user>

I'm using Django 1.11 nowadays.

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