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

27 Aug, 2021
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 geeksforgeeks having an app named geeks.  
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 geeks/models.py,  
Python3
# import the standard Django Model# from built-in libraryfrom django.db import models  # declare a new model with a name "GeeksModel"class GeeksModel(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 geeks folder,  
Python3
from django import formsfrom .models import GeeksModel  # creating a formclass GeeksForm(forms.ModelForm):     # create meta class    class Meta:        # specify model to be used        model = GeeksModel         # 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. In geeks/views.py,  
Python3
from django.shortcuts import render # relative import of formsfrom .models import GeeksModelfrom .forms import GeeksForm  def create_view(request):    # dictionary for initial data with    # field names as keys    context ={}     # add the dictionary during initialization    form = GeeksForm(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,  
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 geeks/views.py,  
Python3
from django.shortcuts import render # relative import of formsfrom .models import GeeksModel  def list_view(request):    # dictionary for initial data with    # field names as keys    context ={}     # add the dictionary during initialization    context["dataset"] = GeeksModel.objects.all()             return render(request, "list_view.html", context)
Create a template in templates/list_view.html,  
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 instance 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. In geeks/views.py,  
Python3
from django.urls import path # importing views from views..pyfrom .views import detail_view urlpatterns = [    path('<id>', detail_view ),]
Let’s create a view and template for the same. In geeks/views.py, 
Python3
from django.shortcuts import render # relative import of formsfrom .models import GeeksModel # pass id attribute from urlsdef detail_view(request, id):    # dictionary for initial data with    # field names as keys    context ={}     # add the dictionary during initialization    context["data"] = GeeksModel.objects.get(id = id)             return render(request, "detail_view.html", context)
Create a template in templates/Detail_view.html,  
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 entries in the database for example, updating an article at geeksforgeeks. In geeks/views.py, 
Python3
from django.shortcuts import (get_object_or_404,                              render,                              HttpResponseRedirect) # relative import of formsfrom .models import GeeksModelfrom .forms import GeeksForm # after updating it will redirect to detail_Viewdef detail_view(request, id):    # dictionary for initial data with    # field names as keys    context ={}      # add the dictionary during initialization    context["data"] = GeeksModel.objects.get(id = id)              return render(request, "detail_view.html", context) # update view for detailsdef 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(GeeksModel, id = id)     # pass the object as instance in form    form = GeeksForm(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 geeks/templates/update_view.html, 
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 geeks/templates/detail_view.html,  
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 geeksforgeeks. In geeks/views.py  
Python3
from django.shortcuts import (get_object_or_404,                              render,                              HttpResponseRedirect) from .models import GeeksModel  # delete view for detailsdef 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(GeeksModel, 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 geeks/urls.py  
Python3
from django.urls import path # importing views from views..pyfrom .views import delete_viewurlpatterns = [    path('<id>/delete', delete_view ),]
Template for delete view includes a simple form confirming whether user wants to delete the instance or not. In geeks/templates/delete_view.html,  
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 
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