otteydw/django_tutorial

Django Blog Tutorial from Corey Schafer: https://www.youtube.com/watch?v=UmljXZIypDc&list=PL-osiE80TeTtoQCKZ03TU5fNfx2UY6U4p

Setup

Install django

pip install -r requirements.txt

Create project

django-admin startproject django_project

Launch the server

python manage.py runserver

Site becomes available at http://localhost:8000/

Start a new app

python manage.py startapp blog

Bootstrap Starter Template

https://getbootstrap.com/docs/4.0/getting-started/introduction/#starter-template

Admin Page

Create the super user

python manage.py makemigrations  # This will show "No changes detected"
python manage.py migrate
python manage.py createsuperuser

Access the admin page: http://localhost:8000/admin/

Migrations

Changing models

You must run the migration whenever models are changed.

python manage.py makemigrations
python manage.py migrate

Real world

Based on Django Migrations Documentation, it looks like makemigrations would normally be run on a pre-prod system. The generated migration file should be committed to source control. Then in production you would only need to run migrate.

You should think of migrations as a version control system for your database schema. makemigrations is responsible for packaging up your model changes into individual migration files - analogous to commits - and migrate is responsible for applying those to your database.

The migration files for each app live in a “migrations” directory inside of that app, and are designed to be committed to, and distributed as part of, its codebase. You should be making them once on your development machine and then running the same migrations on your colleagues’ machines, your staging machines, and eventually your production machines.

Debugging Migrations

Lets say you run the makemigrations and get the following output:

➜  django_project git:(tutorial_part_05) ✗ python manage.py makemigrations
Migrations for 'blog':
  blog/migrations/0001_initial.py
    - Create model Post

You can see the actual sql that will be run during the migrate step by running

python manage.py sqlmigrate blog 0001

Be sure to fill in the appropriate app name and migration number.

Here is the example output:

➜  django_project git:(tutorial_part_05) ✗ python manage.py sqlmigrate blog 0001
BEGIN;
--
-- Create model Post
--
CREATE TABLE "blog_post" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "title" varchar(100) NOT NULL, "content" text NOT NULL, "date_posted" datetime NOT NULL, "author_id" integer NOT NULL REFERENCES "auth_user" ("id") DEFERRABLE INITIALLY DEFERRED);
CREATE INDEX "blog_post_author_id_dd7a8485" ON "blog_post" ("author_id");
COMMIT;

Debugging

You can enter an interactive python shell that has access to all the Django models

python manage.py shell

Sample:

➜  django_project git:(tutorial_part_05) ✗ python manage.py shell
Python 3.12.1 (main, Jan  5 2024, 10:51:10) [Clang 15.0.0 (clang-1500.1.0.2.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)

Create a post from the interactive shell

>>> from blog.models import Post
>>> from django.contrib.auth.models import User
>>> User.objects.all()
<QuerySet [<User: dottey>, <User: testuser>]>

>>> User.objects.first()
<User: dottey>

>>> User.objects.last()
<User: testuser>

>>> User.objects.filter(username='dottey').first()
<User: dottey>

>>> user = User.objects.filter(username='dottey').first()

>>> Post.objects.all()
<QuerySet []>

>>> post_1 = Post(title='Blog 1', content='First Post Content!', author=user)
>>> post_1.save()
>>> Post.objects.all()
<QuerySet [<Post: Post object (1)>]>

After adding a __str__ method to the Post class:

>>> from blog.models import Post
>>> from django.contrib.auth.models import User
>>> Post.objects.all()
<QuerySet [<Post: Blog 1>]>

Get details about the post

>>> post = Post.objects.first()
>>> post
<Post: Blog 1>

>>> post.date_posted
datetime.datetime(2024, 2, 6, 19, 13, 53, 733767, tzinfo=datetime.timezone.utc)

Using post_set to access and create posts:

>>> user.post_set.all()
<QuerySet [<Post: Blog 1>, <Post: Blog 2>]>

>>> user.post_set.create(title='Blog 3', content='Third Post Content!')
<Post: Blog 3>

Crispy Forms

• https://django-crispy-forms.readthedocs.io/en/latest/install.html
• https://pypi.org/project/crispy-bootstrap4/

Add the two requirements

crispy-bootstrap4
django-crispy-forms

Update settings.py

    INSTALLED_APPS = (
        ...
        "crispy_forms",
        "crispy_bootstrap4",
        ...
    )

    CRISPY_ALLOWED_TEMPLATE_PACKS = "bootstrap4"

    CRISPY_TEMPLATE_PACK = "bootstrap4"

Static Files

This is set up for serving static files locally for development purposes. This is not suitable for production.

• Serving static files during development