django sort query result by occurrence count

Question

I've got the flowing two models:

class Item(models.Model):
    Name = models.CharField(max_length = 32)

class Profile(models.Model):
    user = models.ForeignKey(User, unique = True)

    ItemList = models.ManyToManyField(Item, related_name = "user_itemlist")

For Item X I want to get a list of Item objects present in ItemList for all Profile objects that contain X in ItemList, sorted by how many times each object appears.

The best I can do so far is:

Item.objects.filter(user_itemlist__in = User.objects.filter(profile__ItemList = X))

and this returns the list of all Item objects I need, with duplicates (if Item Z is present in ItemList for 10 Profile objects it will appear 10 times in the query result).

How can I sort the result of the above query by the number of times each object appears in the result and remove duplicates? Is there any "django" way to do that?

Answer 1

profiles = Profile.objects.filter(profile__ItemList=X)

Item.objects.filter(
    user_itemlist__in=profiles
).annotate(itemcount=Count('id')).order_by('-itemcount')