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this is a simple question. I'd like to know if it is the same to write:
queryset = Model.objects.filter(field=None) than:
queryset = Model.objects.filter(field__isnull=True) I'm using django 1.8
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In Django queryset we have __isnull to check if a value is null. Here were filtering all the values from MyModel model, which have an alias = Null. exclude allows you to pass multiple arguments, it will the then check for every argument. If your query is still more complex, you can use Django's Q Objects.
Using select_related() Django offers a QuerySet method called select_related() that allows you to retrieve related objects for one-to-many relationships. This translates to a single, more complex QuerySet, but you avoid additional queries when accessing the related objects.
They are equal:
>>> str(Person.objects.filter(age__isnull=True).query) == str(Person.objects.filter(age=None).query) True >>> print(Person.objects.filter(age=None).query) SELECT "person_person"."id", "person_person"."name", "person_person"."yes", "person_person"."age" FROM "person_person" WHERE "person_person"."age" IS NULL >>> print(Person.objects.filter(age__isnull=True).query) SELECT "person_person"."id", "person_person"."name", "person_person"."yes", "person_person"."age" FROM "person_person" WHERE "person_person"."age" IS NULL Exclusion: the Postgres JSON field (see the answer of @cameron-lee)
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