Querying null in JSONField is different between Django 3.2 and 4.0

Question

Let's say I have a Django model with a JSONField:

class Event(models.Model):
    data = models.JSONField()

And I create the following objects:

event1 = Event.objects.create(data={"key": None})
event2 = Event.objects.create(data={"key": "null"})

In Django 3.2.13, the following queries return some results:

Event.objects.filter(data__key=Value("null"))
# [event1]

Event.objects.filter(data__key="null")
# [event2]

In Django 4.0.5, the same queries return different results:

Event.objects.filter(data__key=Value("null"))
# [event1, event2]

Event.objects.filter(data__key="null")
# [event1, event2]

The Django docs aren't clear which results are correct. I would lean towards the v3 results.

Any idea which one is correct? Is this a bug in v4? I filed a ticket in the Django bug tracker here: https://code.djangoproject.com/ticket/33820#ticket

Answer 1

Turns out this is a bug in Django. See the ticket for more information: https://code.djangoproject.com/ticket/33820#ticket