Django ORM - Select All Records from One Table That Do Not Exist in Another Table - django-orm

Question

Lets have 2 models:
class A(models.Model):
f1 = models.CharField()
f2 = models.IntegerField()
f3 = models.BooleanField()
class B(models.Model):
f1 = models.CharField()
f2 = models.IntegerField()
f3 = models.DecimalField()
Lets have this data:
A(f1=rat, f2=100, f3=true)
A(f1=cat, f2=200, f3=true)
A(f1=dog, f2=300, f3=false)
B(f1=eagle, f2=100, f3=3.14)
B(f1=cat, f2=200, f3=9.81)
B(f1=dog, f2=300, f3=100.500)
I need to select objects from table B, that does not have similar data for fields f1, f2 in table A.
In my case it will be:
B(f1=eagle, f2=100, f3=3.14)
The following objects are not relevant, because they exist in both tables (f1 and f2 fields)
B(f1=cat, f2=200, f3=9.81)
B(f1=dog, f2=300, f3=100.500)
Is it possible to select this data using Django ORM?
I tried to find information about Sub-query, but did not find good example.

Answer 1

You can use exclude with Q objects:
from django.db.models import Q
B.objects.exclude(Q(f1__in=A.objects.values_list('f1', flat=True)) & Q(f2__in=A.objects.values_list('f2', flat=True)))

Answer 2

resolved in this way:
from django.db.models import OuterRef, Exists
a_queryset = A.objects.filter(f1=OuterRef('f1'), f2=OuterRef('f2'))
result_queryset = B.objects.filter(~Exists(a_queryset))
# B(f1=eagle, f2=100, f3=3.14)
reverse:
result_queryset = B.objects.filter(Exists(a_queryset))
# B(f1=cat, f2=200, f3=9.81)
# B(f1=dog, f2=300, f3=100.500)