Django 1.7.7 get object count in template through double relation - django

Question

I have 3 models, Entry model and Category model, and I have created intermediate model CategoryEntry.
class Entry(models.Model):
entry_text = models.TextField()
class Category(models.Model):
user = models.ForeignKey(User)
category_text = models.CharField(max_length=200)
entries = models.ManyToManyField(Entry, through='CategoryEntry')
class CategoryEntry(models.Model):
category = models.ForeignKey(Category, related_name="related_entry_categories")
entry = models.ForeignKey(Entry)
viewed = models.BooleanField(default=False)
How can I get in template Users total Entry count.
For example I can get total users Category count with
{{ user.category_set.count }}
So I tried many different ways, but don't get how to follow next relation
{{ user.category_set.entries.count}}
{{ user.category_set.categoryentry_set.count}}
{{ user.category_set.all.categoryentry_set.count}}
{{ user.category_set.related_entry_categories.count }}
Is this even possible (good thing to do) to count in template? Or is there better way?
Thanks!

Answer 1

your queries don't make sense because category_set is a collection of objects rather than a single object, so you cannot simply ask for category_set.entries.count
first you have to think about what you want... do you want:
individual count of entries for each category in category_set?
or total count of entries across all categories in category_set?
For the former you need to annotate the queryset. this will have to be done in the view rather than template because the method needs arguments:
from django.db.models import Count
user_categories = user.category_set.annotate(entry_count=Count('entries'))
# then pass the user_categories queryset into your template along with user
you can then iterate over user_categories in the template to display individual counts:
{% for category in user_categories %}
No. of entries: {{ category.entry_count }}
{% endfor %}
For the latter you can use aggregate, again in the view:
from django.db.models import Count
total = user.category_set.aggregate(entry_count=Count('entries'))
# note that aggregate method returns a dict:
print total['entry_count']
# then pass total['entry_count'] as a value into your template along with user