Django queryset filter for blank FileField?

How do I perform a Django queryset filter looking for blank files in `FileField` fields?

The field isn't null, it has a FileObject in it that doesn't have a file.

I was having this issue too, and finally found the solution!

no_files = MyModel.objects.filter(foo='')

This works because internally, the `FileField` is represented as a local file path in a `CharField`, and Django stores non-files as an empty string `''` in the database.

An alternative solution:
```
no_files = MyModel.objects.filter(foo__in=['',None])
```