How can I get the object count for a model in Django's templates?

Question

I\'m my Django application I\'m fetching all the objects for a particular model like so:

secs = Sections.objects.filter(order__gt = 5)

I pa

Answer 1

Additionally to what Daniel said, Django creates reverse relationships automatically (as Daniel said above) unless you override their names with the related_name argument. In your particular case, you would have something like:

class Book(models.Model):
    section = models.ForeignKey(Section, related_name="books")

Then you can access the section's books count in the template by:

{{ sec.books.count }}

As you intimated in your question.

Answer 2

If Books has a ForeignKey to Sections, then Django will automatically create a reverse relationship from Sections back to Books, which will be called books_set. This is a Manager, which means you can use .filter(), .get() and .count() on it - and you can use these in your template.

{{ sec.books_set.count }}

(By the way, you should use singular nouns for your model names, not plurals - Book instead of Books. An instance of that model holds information for one book, not many.)

Answer 3

As for a 2019 answer. I would suggest making use of related_name while making your ForeignKey to look like that:

section = models.ForeignKey(Section, on_delete=models.SET_NULL, related_name='books')

Then you can use it as follows:

{{ section.books.count }} 

or

{{ section.books|length }}