Python – Django: Filter by values in None, Other

I’m having the same issue as OP in this thread: Django – filtering by “certain value or None” :

I have a field in an data object that can be either null or set to
some integer. I want, given an integer, to filter all the objects with
that integer value OR none:

MyElements.objects.all().filter(value__in=[myInt, None]) # Query 1

However, this line does not work for elements with null value. More
precisely:

MyElements.objects.all().filter(value__in=[None]) # Query 2

returns nothing. whereas

MyElements.objects.all().filter(value = None) # Query 3

returns the null-valued elements.

How can I rewrite the original query (which involves myInt) correctly?

I

know the OP has accepted an answer, but I’m wondering why query 2 didn’t produce any results.

It is executed according to SQL rules. NULL values are not the actual values to be compared. This is an unknown value.

Read more about this here: is null vs == null

In Django, you can get records with NULL values like this:

MyElements.objects.filter(value__isnull = True)

So you need to filter out None in the comparison list first, and then add it to your query by yourself.

from django.db.models import Q
MyElements.objects.filter(Q(value__in = [list_of_vals]) | Q(value__isnull = True))