CODEWITHSUNDEEP
djangodjango-orm
Vlad T.
Vlad T.

Reputation: 2608

Combine two Django queries

I have two related models:

class Category(models.Model):
    pass


class Entry(models.Model):
    category = models.ForeignKey(Category, related_name='entries')
    is_published = models.BooleanField(default=True)

I need to get categories with published entries.

I ended up with two queries:

published = Entry.objects.filter(is_published=True)
categories = Category.objects.filter(entries__in=published)

Can I do this in one query?

Upvotes: 0

Views: 40

Answers (1)

Daniel Roseman
Daniel Roseman

Reputation: 599490

Use the double-underscore to make a query across related objects.

categories = Category.objects.filter(entry__is_published=True)

(Note, your original code would actually only do one query, but it would have a subquery which is likely to be less efficient than the JOIN in my version.)

Upvotes: 3

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