Django Tutorial

1 - Installation
2 - First Steps
3 - The modal layer
4 - The view layer
5 - The template layer
6 - Forms
7 - The development process
8 - The admin
9 - Security

Sources

• https://docs.djangoproject.com/en/1.7/howto/static-files/#configuring-static-files
• https://www.b-list.org/weblog/2006/sep/10/django-tips-laying-out-application/
• https://www.tutorialspoint.com/django/
• https://djangobook.com/

Required modules:

pip install Django pip install Pillow pip install docutils

Next

Change model name User to UserDetails

$ manage.py makemigrations
Did you rename the website.User model to UserDetails? [y/N] y
Migrations for 'website':
  website\migrations\0002_auto_20191118_1400.py
	- Rename model User to UserDetails

You will get the following error:

django.db.utils.NotSupportedError: Renaming the 'website_user' table while in a transaction
is not supported on SQLite < 3.26 because it would break referential integrity. 
Try adding `atomic = False` to the Migration class.

Why ?? https://stackoverflow.com/questions/48549068/django-db-utils-notsupportederror-in-sqlite-why-not-supported-in-sqlite

Open website/migrations/0002_auto....py append in class Migration

atomic = False


$ manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, sessions, website
Running migrations:
  Applying website.0002_auto_20191118_1400... OK

$ manage.py runscript do_migrations --script-args copyDataFromUserDetails

---

https://django-extensions.readthedocs.io/en/latest/runscript.html

INSTALLED_APPS = [
	'website',
	...
	'django_extensions'
]

def run():	#Without arguments
	...

def run(*args):		#With arguments
	...

---

Remove fields username, password, email and add field user_id

user_id = models.IntegerField()

$ manage.py makemigrations
You are trying to add a non-nullable field 'user_id' to userdetails without a default; we can't do that (the database needs something to populate existing rows).
Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows with a null value for this column)
 2) Quit, and let me add a default in models.py
Select an option: 2

user_id = models.IntegerField(null=True)

$ manage.py makemigrations
Migrations for 'website':
  website\migrations\0003_auto_20191118_1406.py
	- Remove field email from userdetails
	- Remove field password from userdetails
	- Remove field username from userdetails
	- Add field user_id to userdetails
	
$ manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, sessions, website
Running migrations:
  Applying website.0003_auto_20191118_1406... OK

$ manage.py runscript do_migrations --script-args setUserIDs

Now that each UserDetails record has user_id populated (not null) we will change the field to be Foreign Key

$ manage.py makemigrations
You are trying to change the nullable field 'user_id' on userdetails to non-nullable without a default; we can't do that (the database needs something to populate existing rows).
Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows with a null value for this column)
 2) Ignore for now, and let me handle existing rows with NULL myself (e.g. because you added a RunPython or RunSQL operation to handle NULL values in a previous data migration)
 3) Quit, and let me add a default in models.py
Select an option: 2
Migrations for 'website':
  website\migrations\0004_auto_20191118_1537.py
	- Alter field user_id on userdetails

$ manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, sessions, website
Running migrations:
  Applying website.0004_auto_20191118_1537... OK