Django CRUD (Create, Retrieve, Update, Delete) Function Based Views

Django is a Python-based web framework which allows you to quickly create web application without all of the installation or dependency problems that you normally will find with other frameworks. Django is based on MVT (Model View Template) architecture and revolves around CRUD (Create, Retrieve, Update, Delete) operations. CRUD can be best explained as an approach to building a Django web application. In general CRUD means performing Create, Retrieve, Update and Delete operations on a table in a database. Let’s discuss what actually CRUD means,

Create – create or add new entries in a table in the database.

Retrieve – read, retrieve, search, or view existing entries as a list(List View) or retrieve a particular entry in detail (Detail View)

Update – update or edit existing entries in a table in the database

Delete – delete, deactivate, or remove existing entries in a table in the database

Illustration of How to create and use CRUD view using an Example. Consider a project named mcatutorialshaving an app namedmcatutorials.

Refer to the following articles to check how to create a project and an app in Django.

• How to Create a Basic Project using MVT in Django?
• How to Create an App in Django ?

After you have a project and an app, let’s create a model of which we will be creating instances through our view. In mcatutorials/models.py,

# import the standard Django Model 
# from built-in library 
from django.db import models 
   
# declare a new model with a name "McatutorialsModel" 
class McatutorialsModel(models.Model): 
  
    # fields of the model 
    title = models.CharField(max_length = 200) 
    description = models.TextField() 
  
    # renames the instances of the model 
    # with their title name 
    def __str__(self): 
        return self.title 

After creating this model, we need to run two commands in order to create Database for the same.

Python manage.py makemigrations
Python manage.py migrate

Now we will create a Django ModelForm for this model. Refer this article for more on modelform – Django ModelForm – Create form from Models. create a file forms.py in mcatutorials folder,

from django import forms 
from .models import McatutorialsModel 
  
  
# creating a form 
class McatutorialsForm(forms.ModelForm): 
  
    # create meta class 
    class Meta: 
        # specify model to be used 
        model = McatutorialsModel 
  
        # specify fields to be used 
        fields = [ 
            "title", 
            "description", 
        ] 

Create View refers to a view (logic) to create an instance of a table in the database. It is just like taking an input from a user and storing it in a specified table.

from django.shortcuts import render 
  
# relative import of forms 
from .models import McatutorialsModel 
from .forms import McatutorialsForm 
  
  
def create_view(request): 
    # dictionary for initial data with  
    # field names as keys 
    context ={} 
  
    # add the dictionary during initialization 
    form = McatutorialsForm(request.POST or None) 
    if form.is_valid(): 
        form.save() 
          
    context['form']= form 
    return render(request, "create_view.html", context) 

Create a template in templates/create_view.html,

< form method="POST" enctype="multipart/form-data"> 
  
    < !-- Security token -->
    {% csrf_token %} 
  
    < !-- Using the formset -->
    {{ form.as_p }} 
      
    < input type="submit" value="Submit"> 
< /form> 

Now visit http://localhost:8000/

To check complete implementation of Function based Create View, visit Create View – Function based Views Django.

Retrieve view is basically divided into two types of views Detail View and List View.

List View refers to a view (logic) to list all or particular instances of a table from the database in a particular order. It is used to display multiple types of data on a single page or view, for example, products on an eCommerce page. In mcatutorials/views.py,

from django.shortcuts import render 
  
# relative import of forms 
from .models import McatutorialsModel 
  
  
def list_view(request): 
    # dictionary for initial data with  
    # field names as keys 
    context ={} 
  
    # add the dictionary during initialization 
    context["dataset"] = McatutorialsModel.objects.all() 
          
    return render(request, "list_view.html", context) 

Create a template in templates/list_view.html,

< div class="main"> 
  
    {% for data in dataset %}. 
  
    {{ data.title }}< br/> 
    {{ data.description }}< br/> 
    < hr/> 
  
    {% endfor %} 
  
< /div> 

Now visit http://localhost:8000/

To check complete implementation of Function based List View, visit List View – Function based Views Django

Detail View refers to a view (logic) to display a particular instnace of a table from the database with all the necessary details. It is used to display multiple types of data on a single page or view, for example, profile of a user.

from django.urls import path 
  
# importing views from views..py 
from .views import detail_view 
  
urlpatterns = [ 
    path('< id>', detail_view ), 
] 

Let’s create a view and template for the same. In mcatutorials/views.py,

from django.shortcuts import render 
  
# relative import of forms 
from .models import McatutorialsModel 
  
# pass id attribute from urls 
def detail_view(request, id): 
    # dictionary for initial data with  
    # field names as keys 
    context ={} 
  
    # add the dictionary during initialization 
    context["data"] = McatutorialsModel.objects.get(id = id) 
          
    return render(request, "detail_view.html", context) 

Create a template in templates/Detail_view.html,

< div class="main"> 
      
    < !-- Specify fields to be displayed -->
    {{ data.title }}< br/> 
    {{ data.description }}< br/> 
  
< /div> 

Let’s check what is there on http://localhost:8000/1

To check complete implementation of Function based Detail View, visit Detail View – Function based Views Django

Update View refers to a view (logic) to update a particular instance of a table from the database with some extra details. It is used to update enteries in the database for example, updating an article at mcatutorials.

from django.shortcuts import (get_object_or_404, 
                              render, 
                              HttpResponseRedirect) 
  
# relative import of forms 
from .models import McatutorialsModel 
from .forms import McatutorialsForm 
  
# after updating it will redirect to detail_View 
def detail_view(request, id): 
    # dictionary for initial data with  
    # field names as keys 
    context ={} 
   
    # add the dictionary during initialization 
    context["data"] = McatutorialsModel.objects.get(id = id) 
           
    return render(request, "detail_view.html", context) 
  
# update view for details 
def update_view(request, id): 
    # dictionary for initial data with  
    # field names as keys 
    context ={} 
  
    # fetch the object related to passed id 
    obj = get_object_or_404(McatutorialsModel, id = id) 
  
    # pass the object as instance in form 
    form = McatutorialsForm(request.POST or None, instance = obj) 
  
    # save the data from the form and 
    # redirect to detail_view 
    if form.is_valid(): 
        form.save() 
        return HttpResponseRedirect("/"+id) 
  
    # add form dictionary to context 
    context["form"] = form 
  
    return render(request, "update_view.html", context) 

Now create following templates in templates folder, In mcatutorials/templates/update_view.html,

< div class="main"> 
    < !-- Create a Form -->
    < form method="POST"> 
        < !-- Security token by Django -->
        {% csrf_token %} 
  
        < !-- form as paragraph -->
        {{ form.as_p }} 
  
        < input type="submit" value="Update"> 
    < /form> 
  
< /div> 

In mcatutorials/templates/detail_view.html,

< div class="main"> 
    < !-- Display attributes of instance -->
    {{ data.title }} < br/> 
    {{ data.description }} 
< /div>

Let’s check if everything is working, visithttp://localhost:8000/1/update.

To check complete implementation of Function based update View, visit Update View – Function based Views Django

Delete View refers to a view (logic) to delete a particular instance of a table from the database. It is used to delete entries in the database for example, deleting an article at mcatutorialsformca. In mcatutorials/views.py

from django.shortcuts import (get_object_or_404, 
                              render,  
                              HttpResponseRedirect) 
  
from .models import McatutorialsModel 
  
  
# delete view for details 
def delete_view(request, id): 
    # dictionary for initial data with  
    # field names as keys 
    context ={} 
  
    # fetch the object related to passed id 
    obj = get_object_or_404(McatutorialsModel, id = id) 
  
  
    if request.method =="POST": 
        # delete object 
        obj.delete() 
        # after deleting redirect to  
        # home page 
        return HttpResponseRedirect("/") 
  
    return render(request, "delete_view.html", context)

Now a url mapping to this view with a regular expression of id, In mcatutorials/urls.py

from django.urls import path 
  
# importing views from views..py 
from .views import delete_view 
urlpatterns = [ 
    path('< id>/delete', delete_view ), 
] 

Template for delete view includes a simple form confirming whether user wants to delete the instance or not. In mcatutorials/templates/delete_view.html,

< div class="main"> 
    < !-- Create a Form -->
    < form method="POST"> 
        < !-- Security token by Django -->
        {% csrf_token %} 
        Are you want to delete this item ? 
        < input type="submit" value="Yes" /> 
        < a href="/">Cancel < /a> 
    < /form> 
< /div>

Everything ready, now let’s check if it is working or not, visit http://localhost:8000/2/delete

To check complete implementation of Function based Delete View, visit Delete View – Function based Views Django