get foreign key objects in a single query - Django

Question

I have 2 models in my django code:

class ModelA(models.Model):
    name = models.CharField(max_length=255)
    description = models.CharField(max_length=255)         


        

Answer 1

The reason .select_related() didn't work, is that .select_related() is used to follow foreign keys. Your ModelA doesn't have a foreign key to ModelB. Its ModelB that has a foreign key to ModelA. (so a ModelA instance can have multiple ModelB instances related to it).

You could use this to do it in 2 queries, and a bit of python code:

list_b = ModelB.objects.all()
list_a = ModelA.objects.all()
for a in list_a:
    a.additional_data = [b for b in list_b if b.modela_link_id==a.id]