CODEWITHSUNDEEP
pythondjangodjango-modelsdjango-querysetdjango-filters
Edmond
Edmond

Reputation: 69

Django .objects,get for merged querysets from different models

I have an abstract base model ('Base') from which two models inherit: 'Movie' and 'Cartoon'. I display a list of both movies and cartoons to the user (with the help of itertools.chain). Then I want to give the user the opportunity to delete any of these items, without knowing in advance whether it is a movie or a cartoon. I am trying to do it like this:

        ...

        movies = Movie.objects.filter(user_created=userlist).order_by('title')
        cartoons = Cartoon.objects.filter(user_created=userlist).order_by('title')

        all_items = list(chain(movies, cartoons))

        item = all_items.get(id=item_id)
        item.delete()

But then PyCharm states,

Unresolved attribute reference 'get' for class 'list'

I understand why this happens but I don't know how to avoid it. Is there any way to merge two querysets from different models and apply get or filter without removing the abstract base model and creating a physical parent model?

Upvotes: 0

Views: 392

Answers (2)

nthall
nthall

Reputation: 2915

You could use the ContentTypes framework for a generic and reusable solution to this for an arbitrary number of different models. But I also wonder why Cartoon and Movie must be different types to begin with; it may be worth spending a little time thinking about whether you can use a single model for both types of media - deletion of an arbitrary instance is just one of many cases where a single model will be more straightforward than relying on something like ContentTypes.

EDIT: For more info on ContentTypes. You could either create a base model with a generic relation (you said you didn't want to do this), or for the deletion you could include app label and model name in the request data alongside item id, enabling lookups like:

    media_type = ContentType.objects.get(app_label=app_label, model=model_name)
    instance = media_type.get_object_for_this_type(id=item_id)
    instance.delete()

what's nice about this approach is you'd barely have to change your model structure.

Upvotes: 1

NaSir HuSSaiN
NaSir HuSSaiN

Reputation: 315

you can first find the index using index() method and then can get item by all_items[given_index].delete()

Upvotes: 0

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