How to Make Python Web Application CRUD Using Django

You might also want to learn that Django has been created with front-end developers in mind. Above all, “Django’s template language is designed to feel comfortable and easy-to-learn to those used to working with HTML, like designers and front-end developers. But it is also flexible and highly extensible, allowing developers to augment the template language as needed.”One of the most common tasks when developing web applications is to write, create, read, update, and delete functionality (CRUD) for each table you have.

In this post, we briefly cover the steps needed to create a CRUD app in Django; the steps we will need are:

• Install Django and start a new project
• Make an App
• Create the Model
• Make the Admin Interface (optional)
• Create the View
• Define the URLs (i.e., URL to View mapping)
• Create the Templates

Install Django and Start New Project

First, we need to install Django and start a new Django project; we will name it my_proj:

pip install django
django-admin startproject my_proj
cd my_proj

Create a New App

From the Django project directory, we will create a new app called “books” to store our books collection:

./manage.py startapp books

We will also need to register the new app in our Django project, add the app “books” to the INSTALLED_APPS in your my_proj/settings.py:

INSTALLED_APPS = (
 :
 'books',
 :
 )

Create the Model

The model file would be books/models.py:

from django.db import models
from django.urls import reverse

class Book(models.Model):
name = models.CharField(max_length=200)
pages = models.IntegerField()

def __str__(self):
return self.name

def get_absolute_url(self):
return reverse('book_edit', kwargs={'pk': self.pk})

After defining the model, you need to provide it to the database:

./manage.py makemigrations 
./manage.py migrate

To create the table for the new model.

Admin Interface (Optional)

Above all, Django will give you free CRUD interface from the admin site, define the file books/admin.py as:

from django.contrib import admin
from books.models import Book

admin.site.register(Book)

The Views

We will use Django Class-based views to create our app pages, hence, the file books/views.py would look like:

from django.http import HttpResponse
from django.views.generic import ListView, DetailView
from django.views.generic.edit import CreateView, UpdateView, DeleteView
from django.urls import reverse_lazy

from books.models import Book

class BookList(ListView):
model = Book

class BookView(DetailView):
model = Book

class BookCreate(CreateView):
model = Book
fields = ['name', 'pages']
success_url = reverse_lazy('book_list')

class BookUpdate(UpdateView):
model = Book
fields = ['name', 'pages']
success_url = reverse_lazy('book_list')

class BookDelete(DeleteView):
model = Book
success_url = reverse_lazy('book_list')

Define the URLs

We need to define app URLs in the file books/urls.py (create the file):

from django.urls import path

from . import views

urlpatterns = [
path('', views.BookList.as_view(), name='book_list'),
path('view/<int:pk>', views.BookView.as_view(), name='book_view'),
path('new', views.BookCreate.as_view(), name='book_new'),
path('view/<int:pk>', views.BookView.as_view(), name='book_view'),
path('edit/<int:pk>', views.BookUpdate.as_view(), name='book_edit'),
path('delete/<int:pk>', views.BookDelete.as_view(), name='book_delete'),
]

It should be noted that this URL wouldn’t work unless you include the books/urls.py in the main URLs file my_proj/urls.py:

# Make sure you import "include" function
from django.urls import include

urlpatterns = [
:
path('books/', include('books.urls')),
:
]

Templates

books/templates/books/book_list.html You can use this file to view the list:

<thead>
<tr>
<th>Name</th>
<th>Pages</th>
<th>View</th>
<th>Edit</th>
<th>Delete</th>
</tr>
</thead>
<tbody>
{% for book in object_list %}
<tr>
<td>{{ book.name }}</td>
<td>{{ book.pages }}</td>
<td><a href="{% url "book_view" book.id %}">view</a></td>
<td><a href="{% url "book_edit" book.id %}">edit</a></td>
<td><a href="{% url "book_delete" book.id %}">delete</a></td>
</tr>
{% endfor %}
</tbody>
</table>

<a href="{% url "book_new" %}">New</a>

books/templates/books/book_detail.html You can use this file to view details:

<h1>Books</h1>

<table border="1">
<h1>Book Details</h1>
<h2>Name: {{object.name}}</h2>
Pages: {{ object.pages }}

books/templates/books/book_form.html This file is used to Edit and Update views:

<h1>Book Edit</h1>
<form method="post">{% csrf_token %}
{{ form.as_p }}
<input type="submit" value="Submit" />
</form>

books/templates/books/book_confirm_delete.html We can use this file to Delete certain information:

<h1>Book Delete</h1>
<form method="post">{% csrf_token %}
Are you sure you want to delete "{{ object }}" ?
<input type="submit" value="Submit" />
</form>

Test It

Finally, everything in place, now we can run the development web server:

./manage.py runserver

Also, to test the admin interface, we need to create a user first:

./manage.py createsuperuser

Function-Based View Version

The example above uses Class Based Views (or CBV for short) to implement the views, what we will cover now is how to implement the same functionality but with Function Based Views, i.e., using functions instead of classes; therefore, we will be using the same templates:

books/views.py:

from django.shortcuts import render, redirect, get_object_or_404
from django.forms import ModelForm

from books.models import Book

class BookForm(ModelForm):
class Meta:
model = Book
fields = ['name', 'pages']

def book_list(request, template_name='books/book_list.html'):
book = Book.objects.all()
data = {}
data['object_list'] = book
return render(request, template_name, data)

def book_view(request, pk, template_name='books/book_detail.html'):
book= get_object_or_404(Book, pk=pk) 
return render(request, template_name, {'object':book})

def book_create(request, template_name='books/book_form.html'):
form = BookForm(request.POST or None)
if form.is_valid():
form.save()
return redirect('book_list')
return render(request, template_name, {'form':form})

def book_update(request, pk, template_name='books/book_form.html'):
book= get_object_or_404(Book, pk=pk)
form = BookForm(request.POST or None, instance=book)
if form.is_valid():
form.save()
return redirect('book_list')
return render(request, template_name, {'form':form})

def book_delete(request, pk, template_name='books/book_confirm_delete.html'):
book= get_object_or_404(Book, pk=pk) 
if request.method=='POST':
book.delete()
return redirect('book_list')
return render(request, template_name, {'object':book})

books/urls.py:

from django.urls import path

from books import views

urlpatterns = [
path('', views.book_list, name='book_list'),
path('view/<int:pk>', views.book_view, name='book_view'),
path('new', views.book_create, name='book_new'),
path('edit/<int:pk>', views.book_update, name='book_edit'),
path('delete/<int:pk>', views.book_delete, name='book_delete'),
]

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