Django prefetch_related() in ListView class based view - django

Question

I have a simple blog with 2 models: one for Post and one for Comment, like so:
class Post(models.Model):
title = models.CharField(max_length=100)
# content = models.TextField()
content = RichTextUploadingField(blank=True, null=True, config_name='claudiu_cfg')
date_posted = models.DateTimeField(default=timezone.now)
author = models.ForeignKey(User, on_delete=models.CASCADE)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('post-detail', kwargs={'pk': self.pk})
class Comment(models.Model):
author = models.CharField(max_length=20)
text = models.TextField(max_length=350)
date_posted = models.DateTimeField(default=timezone.now)
post = models.ForeignKey(Post, on_delete=models.CASCADE)
def __str__(self):
return self.author
I want to display all posts (paginated) and how many comments each have.
My views.py:
class PostListView(ListView):
model = Post
template_name = 'blog/home.html'
context_object_name = 'posts'
ordering = ['-date_posted']
paginate_by = 5
Just like this i was getting all posts, but now i want to access the Comment table with as little selects as possible.
I know one way to do this is define a queryset and did it like this:
class PostListView(ListView):
model = Post
template_name = 'blog/home.html' # <app>/<model>_<viewtype>.html
context_object_name = 'posts'
ordering = ['-date_posted']
paginate_by = 5
queryset = Post.objects.all().prefetch_related()
However that does not access the Comment data.
Then i tried to overrite the get_queryset() function hopping to get the desired result. Still no success.
def get_queryset(self):
posts = Post.objects.all().prefetch_related('pk__comment').all()
comments = Comment.objects.all().prefetch_related('post')
print(dir(posts))
print('---------------------')
print(posts._prefetch_done)
return posts.order_by('-date_posted')
That still doesnt work and i cant understand where to go from here.
I did read the documentation, but that still didnt help me.
Please help, as i have nobody to ask for help when it comes to django.
It looks like the solution was closer than i expected, based on responses from
#dirkgroten i managed to fix my issue like so:
class PostListView(ListView):
model = Post
template_name = 'blog/home.html' # <app>/<model>_<viewtype>.html
context_object_name = 'posts'
ordering = ['-date_posted']
paginate_by = 5
queryset = Post.objects.all().prefetch_related('comment_set').all()
To display the number of comments in my template, in a for loop i added:
{{ post.comment_set.all|length }}
Thank you, without your help it would have taken me atleast a few more hours if not days.