使用反向外键查找的Django ListView

Question

If I have code as follows:

Person

Email
  FK(Person)

Phone
  FK(Person)

Address
  FK(Person)

And I want to display a ListView with each person and a phone number, email and address for each of them, all()[0] is good enough, how would I go about creating a QuerySet to pass into ListView?

Thanks

Answer 1

Are the relations one-to-one or one-to-many? If one-to-one, you can get all references in a single query using Django's aggregation features. (Edit: sorry, not the references, only their pks) For instance:

from django.db.models import Min
Person.objects.all().annotate(email=Min('email'), phone=Min('phone'), address=Min('address'))

I don't know whether it will integrate well with ListView, though... Maybe using OneToOneField will work in this case (even without the aggregation), I'm not sure.

If the relations are one-to-many, I'm afraid you won't be able to do that in a single query. As you probably know already, given a Person object you can get the related models using the _set suffix: email_set , phone_set and address_set . But to access them, you'd need other queries (more database hits).