Django models

1. Create Model

Create a model in the models.py file.

models.py

from django.db import models
 
class Post(models.Model):
    title = models.CharField(max_length=100)
    content = models.TextField()
    date_posted = models.DateTimeField(auto_now_add=True)
    # Write your fields here ...

2. Migrate Model

Migrate the model to the database.

Terminal

python manage.py makemigrations
python manage.py migrate

makemigrations command is used to create new migrations based on the changes you have made to your models.
migrate command is used to apply and unapply migrations.

3. Register Model

admin.py

from django.contrib import admin
from .models import Post
 
admin.site.register(Post)

4. Create Superuser

Create a superuser for the admin dashboard.

Terminal

python manage.py createsuperuser

Username: admin
Email address:
Password:
Password (again):
Superuser created successfully.

5. Django Signals

When you want to upload a default image for every user whenever a user creates a profile on the site.

Second example could be when you want to assign an anonymous account whenever a user creates an account.

signals.py

from django.db.models.signals import post_save
from django.contrib.auth.models import User
from django.dispatch import receiver
from .models import Profile
 
@receiver(post_save, sender=User)
def create_profile(sender, instance, created, **kwargs):
    if created:
        Profile.objects.create(user=instance)
 
@receiver(post_save, sender=User)
def save_profile(sender, instance, **kwargs):
    instance.profile.save()

User is the model that sends the signal.
receiver is the function that gets the signal and performs some task.
post_save is the signal that is sent when a user is saved.
create_profile is the function that creates a profile for the user.
save_profile is the function that saves the profile.

Import signals module to make sure that signals are imported when the app is ready.

apps.py

from django.apps import AppConfig
 
class UsersConfig(AppConfig):
    name = 'users'
 
    def ready(self):
        import users.signals

6. Query Model

Query the model in the views.

views.py

from .models import Post
 
def home(request):
    posts = Post.objects.all()
    return render(request, 'blog/home.html', {'posts': posts})

Post.objects.all() is used to get all the posts from the database.

7. Create Model Form

Create a model form in the forms.py file.

forms.py

from django import forms
from .models import Post
 
class PostForm(forms.ModelForm):
    class Meta:
        model = Post
        fields = ['title', 'content']

8. Create Model Form View

Create a model form view in the views.

views.py

from django.shortcuts import redirect
from .forms import PostForm
 
def create_post(request):
    if request.method == 'POST':
        form = PostForm(request.POST)
        if form.is_valid():
            form.save()
            return redirect('home')
    else:
        form = PostForm()
    return render(request, 'blog/create_post.html', {'form': form})

PostForm(request.POST) is used to get the form data from the request.
form.is_valid() is used to check if the form is valid.
form.save() is used to save the form data to the database.

9. Update Model Form View

Update a model form view in the views.

views.py

from django.shortcuts import redirect, get_object_or_404
from .models import Post
 
def update_post(request, pk):
    post = get_object_or_404(Post, pk=pk)
    if request.method == 'POST':
        form = PostForm(request.POST, instance=post)
        if form.is_valid():
            form.save()
            return redirect('home')
    else:
        form = PostForm(instance=post)
    return render(request, 'blog/update_post.html', {'form': form})

get_object_or_404(Post, pk=pk) is used to get the post object from the database.
PostForm(request.POST, instance=post) is used to get the form data from the request and the post object from the database.

10. Delete Model Form View

Delete a model form view in the views.

views.py

from django.shortcuts import redirect, get_object_or_404
from .models import Post
 
def delete_post(request, pk):
    post = get_object_or_404(Post, pk=pk)
    post.delete()
    return redirect('home')

post.delete() is used to delete the post object from the database.

6. Static & Media Files All Fields