Book Image

Web Development with Django Cookbook- Second Edition - Second Edition

By : Aidas Bendoraitis
Book Image

Web Development with Django Cookbook- Second Edition - Second Edition

By: Aidas Bendoraitis

Overview of this book

Django is a web framework that was designed to strike a balance between rapid web development and high performance. It has the capacity to handle applications with high levels of user traffic and interaction, and can integrate with massive databases on the backend, constantly collecting and processing data in real time. Through this book, you'll discover that collecting data from different sources and providing it to others in different formats isn't as difficult as you thought. It follows a task-based approach to guide you through all the web development processes using the Django framework. We’ll start by setting up the virtual environment for a Django project and configuring it. Then you’ll learn to write reusable pieces of code for your models and find out how to manage database schema changes using South migrations. After that, we’ll take you through working with forms and views to enter and list data. With practical examples on using templates and JavaScript together, you will discover how to create the best user experience. In the final chapters, you'll be introduced to some programming and debugging tricks and finally, you will be shown how to test and deploy the project to a remote dedicated server. By the end of this book, you will have a good understanding of the new features added to Django 1.8 and be an expert at web development processes.
Table of Contents (18 chapters)
Web Development with Django Cookbook Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Changing a foreign key to the many-to-many field


This recipe is a practical example of how to change a many-to-one relation to many-to-many relation, while preserving the already existing data. We will use both schema and data migrations for this situation.

Getting ready

Let's consider that you have the Idea model with a foreign key pointing to the Category model, as follows:

# demo_app/models.py
# -*- coding: UTF-8 -*-
from __future__ import unicode_literals
from django.db import models
from django.utils.translation import ugettext_lazy as _
from django.utils.encoding import python_2_unicode_compatible

@python_2_unicode_compatible
class Category(models.Model):
    title = models.CharField(_("Title"), max_length=200)

    def __str__(self):
        return self.title

@python_2_unicode_compatible
class Idea(models.Model):
    title = model.CharField(_("Title"), max_length=200)
    category = models.ForeignKey(Category,
        verbose_name=_("Category"), null=True, blank=True)

    def __str__...