When I go to a post, I can’t get data from the database for this particular post, how to implement it?

Question

Django

I display all the records that are in the database on the site. When I go to the link, a link is generated based on the ID.
But on the post page, I can’t get data from the database for this particular post.

URLs

urlpatterns = [
    url(r'^$', views.index, name='index'),
    url(r'^$', ListView.as_view(queryset=AllFilms.objects.all().order_by("-date")[:12], template_name="main/homepage.html")),
    url(r'^(?P<pk>\d+)$', DetailView.as_view(model = AllFilms, template_name="main/post.html"))
    ]

views

def index(request):
  posts = AllFilms.objects.all()
  return render(request, 'main/homepage.html', context = {'posts' : posts})

As I understood from the lesson on which I write the case in the urls file, but for some reason I did not understand what exactly I did wrong . The
request is as follows:

{% extends "main/wrapper.html" %}

{% block content %}
  <a>{{ film.title }}</a>
{% endblock %}

How to properly describe a request?

Answer 1

In general, use class based veiws, that is, class-based views. Here I will give an example of displaying a list of books (without inheritance from ListView, in order to better understand how it works). Suppose these books will be cards in the template and each card has a button to go to that book.
In the model class, you need to define the get_absolute_url method. At the end of the answer, you will understand why.
models.py
See the documentation for what reverse is.

class Book(models.Model):
    title = models.CharField(...)
    ...

    def get_absolute_url(self):
        return reverse("book-detail-page-url", args=[str(self.id)]

urls.py
Create urls for a list of books and for a specific book with a specific id.

urlpatterns = [
    path("books/", BooksListView().as_view(), name="books-page-url"),
    path("book/<id>/", BookDetailView().as_view(), name="book-detail-page-url")
]

views.py

class BookListView(View):
    def get(self, request):
        books = Book.objects.all()
        return render(request, "books.html", context={"books": books})


class BookDetailView(View):
    def get(request, id):
        book = Book.objects.filter(id=id)
        return render(request, "book_detail.html", context={"book": book})

books.html
To navigate to a specific book on a button, Janga will use the same get_absolute_url method. What does this method actually do? When accessed, it takes the user to a url named "book-detail-page-url" i.e. "book/id/". We pass this same ID in the same method through args.

...
{% for book in books %}
    {{ book.title }}
    ...
    <a href="{{ book.get_absolute_url }}" class="btn btn-primary">Подробнее</a>
    ...
{% endfor %}

book_detail.html

...
{{ book.title }}
...