gist.md

Django Cheat Sheet

Creating app

python manage.py startapp pages

Add your app to project: in installed_apps

INSTALLED_APPS = [
    'pages.apps.PagesConfig',
]

Install: autopep8

pip install autopep8

Configuring Template Directories:

TEMPLATES = [
         {
             # ...
             'DIRS': [os.path.join(BASE_DIR, 'templates')],
             # ...
         },
     ]

To run collectstatic change setting: For static files

# if os not imported
import os

STATIC_ROOT = os.path.join(BASE_DIR, 'static)
STATICFILES_DIRS = [
    os.path.join(BASE_DIR, 'btre/static')
]

command to gather all static files from your apps and place them in the 'STATIC_ROOT' directory

python manage.py collectstatic

Changing to Static Links:

<!-- Declaration -->
{% load static %}

<!-- static files -->
<link rel="stylesheet" href="{% static css/style.css %}">

<!-- page links - here index is refer the name declare in views -->
<a href="{% url 'index' %}">Home</a>

Your Template structure

base.html part in separate folder:

base.html
partials
    | _navbar.html
    | _footer.html
    | _topbar.html

Conditionals in jinja:

<li
    {% if '/' == request.path %}
        class="nav-item active mr-3"
    {% else %}
        class="nav-item mr-3"
    {% endif %}
    >

Mac Postgres Setup:

After Installation Postgres

Config postgres: Open postgres

postgres=#  \password postgres
Enter new password: 
Enter it again:
postgres=# CREATE DATABASE btredb OWNER postgres;

<!-- list database Check -->
postgres=#  \l

<!-- Exit -->
postgres=# \q

Windows Postgres setup on Djagno Project: (Connect Django with Postgres Database) - Run Migrate

Create server from right click on Server:

Configure postgres with django:

pip install psycopg2

pip install psycopg2-binary

Change setting.py:

DATABASE = {
    'ENGINE': 'django.db.backends.postgres',
    'NAME': 'btredb',
    'USER': 'postgres',
    'PASSWORD': '123456',
    'HOST': 'localhost',
}

Run migration: with this postgres database can access the django tables

python manage.py migrate

Make Migrations

make migration: after creating models

python manage.py makemigrations

Before make Migrations

Install Pillow: required for ImageField

pip install Pillow

To use ImageField Install

Install Pillow: required for ImageField

pip install Pillow

list out actual sql created fields after makemigrations:

python manage.py sqlmigrate listings 0001

• Do again migrate command

python manage.py migrate

It reflects the model changes into database

To active admin area

Creating superuser:

python manage.py createsuperuser

Upload Media

Change Setting:

import os

# Media Folder Settings
MEDIA_ROOT = os.path.join(BASE_DIR, 'media')
MEDIA_URL = '/media/'

Change project/urls.py:

from django.conf import settings
from django.conf.urls.static import static
urlpatterns = [
    path('admin/', admin.site.urls),
] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

Change view list in listing/admin.py

class ListingAdmin(admin.ModelAdmin):
    list_display = ('id', 'title', 'is_published', 'price', 'list_date', 'realtor')
    list_display_links = ('id', 'title')
    list_filter = ('realtor', 'is_published')
    list_editable = ('is_published',)
    search_fields = ('title', 'description', 'address', 'city', 'state', 'zipcode', 'price')
    list_per_page = 25

admin.site.register(Listing, ListingAdmin)

Install Pylint for no-error shows in vs code:

pip install pylint-django

Humanize

set settings

INSTALLED_APPS = [
    'django.contrib.humanize',
]

Include:

{% load humanize %}

Delete Migrations

Delete migrations:

python manage.py migrate your_app zero

# This will drop all tables from your_app

# If you want, since you said you want to start over, you can delete your migrations folder, or maybe rename the folder, create a new migrations folder and run

python manage.py makemigrations your_app
python manage.py migrate your_app

How to drop all the tables in a PostgresSQL database:

-- 1. By dropping the schema
DROP SCHEMA public CASCADE;
CREATE SCHEMA public;

GRANT ALL ON SCHEMA public TO postgres;
GRANT ALL ON SCHEMA public TO public;

In this method, we get all the tables in a schema and delete the tables individually using the DROP TABLE command. This method is suitable for the production environment, as other objects in the schema are retained.

PostgresSQL stores all the tables and the table metadata on its record table called pg_table.

We select all the tables from pg_tables whose schemaName is public. Using subquery, we delete the tables from the schema.

-- 2. By dropping individual tables
SELECT
  'DROP TABLE IF EXISTS "' || tablename || '" CASCADE;' 
from
  pg_tables WHERE schemaname = 'public';