How to Make Python Web Application CRUD Using Django
Print Friendly, PDF & Email

Introduction

Django is a free, open-source framework for web applications written in Python. A framework is nothing more than a collection of modules that facilitate development. They are grouped and allow you to create apps or websites from an existing source, rather than from scratch.

This is how websites-even simple ones developed by a single person-can still have advanced functionality such as support for authentication, management, and admin panels, contact fields, comment boxes, support for uploading files, and more. In other words, if you were designing a website from scratch, these components would need to be created yourself. By using a framework; instead, those components are already installed, they need to be properly configured to suit your site.

The official project site defines Django as “a high-level Python Web framework that encourages rapid development and clean, pragmatic design. Built by experienced developers, it takes care of much of the hassle of Web development, so you can focus on writing your app without needing to reinvent the wheel. Moreover, it is free and open-source.”

Benefits

Django offers a large assortment of modules you can use in your projects. Firstly, there are frameworks to save developers a lot of time and headaches wasted, and Django is no different.

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'),
]

We hope you enjoyed the blog. If you like it, please share it with your friends and on your social media handles. We will be happy to hear your feedback. If you have any questions, please do not hesitate to ask them. To know more about our services, please visit Loginworks Softwares Inc.

LEAVE A REPLY

Please enter your comment!
Please enter your name here