Complex Django query over foreign keys

Question

I have two models in the same application. The application is called "News", and it has two classes in its model called "Article" and "Category".

class Category(models.Model):
    name = models.CharField(_("Name"), max_length=100)
    slug = models.SlugField(_("Slug"), max_length=100, unique=True)

class Article(models.Model):
    category = models.ForeignKey(Category, verbose_name=_("Category"))
    archived = models.BooleanField(_("Archive this?"), default=False)

I want to create a query that shows me all of the articles which are archived but grouped by category.

How would I accomplish this efficiently?

Answer 1

Article.objects.filter(archived=True).order_by('category')

i am editing this to get more info to try and help out.

given:

• cat1
  • art1
  • art2-archived
  • art3
• cat2
  • art4
  • art5
  • art6-archived
• cat3
  • art7-archived
  • art8-archived
  • art9

what would you want your queryset to contain?

Answer 2

Isn't this what you want?

class Article(models.Model):
    category = models.ForeignKey(Category, related_name='articles')
    archived = models.BooleanField(default=False)

categories = Category.objects.select_related("articles").filter(articles__archived=True)

Answer 3

c = Category.objects.filter(article__archived=True)