To illustrate the query expressions, let's create the viral video detail view and plug it into the URL configuration, as follows:

1. Create the viral video list and detail views in views.py as follows:

# myproject/apps/viral_videos/views.py
import logging

from django.conf import settings
from django.db import models
from django.utils.timezone import now, timedelta
from django.shortcuts import render, get_object_or_404
from django.views.generic import ListView

from .models import ViralVideo

POPULAR_FROM = getattr(settings, "VIRAL_VIDEOS_POPULAR_FROM", 500)

logger = logging.getLogger(__name__)


class ViralVideoList(ListView):
    template_name = "viral_videos/viral_video_list.html"
    model = ViralVideo


def viral_video_detail(request, pk):
    yesterday = now() - timedelta(days=1)

    qs = ViralVideo.objects.annotate(
        total_views=models.F("authenticated_views") + 
         models.F("anonymous_views"),
        label=models.Case(
            models.When(total_views__gt=POPULAR_FROM, 
             then=models.Value("popular")),
            models.When(created__gt=yesterday, 
             then=models.Value("new")),
            default=models.Value("cool"),
            output_field=models.CharField(),
        ),
    )

    # DEBUG: check the SQL query that Django ORM generates
    logger.debug(f"Query: {qs.query}")

    qs = qs.filter(pk=pk)
    if request.user.is_authenticated:
        qs.update(authenticated_views=models
         .F("authenticated_views") + 1)
    else:
        qs.update(anonymous_views=models.F("anonymous_views") + 1)

    video = get_object_or_404(qs)

    return render(request, "viral_videos/viral_video_detail.html", 
     {"video": video})

2. Define the URL configuration for the app as follows:
   

# myproject/apps/viral_videos/urls.py
from django.urls import path

from .views import ViralVideoList, viral_video_detail

app_name = "viral_videos"


urlpatterns = [
    path("", ViralVideoList.as_view(), name="viral_video_list"),
    path("<uuid:pk>/", viral_video_detail, 
     name="viral_video_detail"),
]

3. Include the URL configuration of the app in the project's root URL configuration as follows:
   

# myproject/urls.py
from django.conf.urls.i18n import i18n_patterns
from django.urls import include, path

urlpatterns = i18n_patterns(
path("viral-videos/", include("myproject.apps.viral_videos.urls", namespace="viral_videos")),
)

4. Create a template for the viral video list view as follows:
   

{# viral_videos/viral_video_list.html #}
{% extends "base.html" %}
{% load i18n %}

{% block content %}
    <h1>{% trans "Viral Videos" %}</h1>
    <ul>
        {% for video in object_list %}
            <li><a href="{{ video.get_url_path }}">
             {{ video.title }}</a></li>
        {% endfor %}
    </ul>
{% endblock %}

5. Create a template for the viral video detail view as follows:

{# viral_videos/viral_video_detail.html #}
{% extends "base.html" %}
{% load i18n %}

{% block content %}
    <h1>{{ video.title }}
        <span class="badge">{{ video.label }}</span>
    </h1>
    <div>{{ video.embed_code|safe }}</div>
    <div>
        <h2>{% trans "Impressions" %}</h2>
        <ul>
            <li>{% trans "Authenticated views" %}:
                {{ video.authenticated_views }}
            </li>
            <li>{% trans "Anonymous views" %}:
                {{ video.anonymous_views }}
            </li>
            <li>{% trans "Total views" %}:
                {{ video.total_views }}
            </li>
        </ul>
    </div>
{% endblock %}

6. Set up the administration for the viral_videos app as follows, and add some videos to the database when you are finished:

# myproject/apps/viral_videos/admin.py
from django.contrib import admin
from .models import ViralVideo

@admin.register(ViralVideo)
class ViralVideoAdmin(admin.ModelAdmin):
    list_display = ["title", "created", "modified"]