Django update view


Django Update View

  • Django update view is used to update a single record of the database table.
  • It shows an editable form to the user with the current row data.
  • User can make the changes to the form and on submit it then it will save the data to the database table.

Contact Model


from django.db import models

class Contact(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=30)
    email = models.EmailField(max_length=255)
    phone = models.CharField(max_length=10, null=True)

    class Meta:
        db_table = "contact"

form template


<form action="" method="POST" enctype="multipart/form-data">
    {% csrf_token %}
    {{ form.as_table }}
    <input type="submit" value="submit" />

function based update view

  • It's simple function handles both GET and POST requests
    • GET - displays the form to the user.
    • POST - recieves the user submitted info
  • Let's looke at code below.
from django.http import HttpResponse
from django.shortcuts import render, get_object_or_404
from my_app.models import Contact
from my_app.forms import ContactModelForm

def fbv_update_view(request, pk):
    obj = get_object_or_404(Contact, id=pk)
    if request.method.lower() == 'post':
        form = ContactModelForm(request.POST, instance=obj)
        if form.is_valid():
            return HttpResponse("<h1>Updated</h1>")
        form = ContactModelForm(instance=obj)
    context = {'form': form}
    return render(request, 'form_template.html', context)
  • get_object_or_404 gets the object from the db if found otherwise throws HTTP 404 error.
  • For GET request
    • render the html template with form
    • ContactModelForm(instance=obj) loads the initial data
  • For POST request
    • validates the form ContactModelForm(request.POST, instance=obj)
    • save the form if it's valid otherwise renders the form template with errors.

class based update view

  • Django provides a generic view UpdateView to update the table row.
from django.http import HttpResponse
from django.views.generic.edit import UpdateView
from my_app.models import Contact
from my_app.forms import ContactModelForm

class CBVUpdateView(UpdateView):
    form_class = ContactModelForm
    template_name = 'form_template.html'
    pk_url_kwarg = 'pk'
    model = Contact

    def form_valid(self, form):
        return HttpResponse("<h1>Updated</h1>")
  • Django provides the generic view class UpdateView.
  • It contains the inbuilt funcitonality which we implemented in the function based view.
  • In order to work with UpdateView we need to provider attributes form_class, template_name, pk_url_kwarg and model or methods get_object() or get_queryset()
    • template_name - used to render the template
    • pk_url_kwarg - used to identify the object in the database
    • model or get_object() or get_queryset() - used to get the object using pk_url_kwarg

configure the urls

  • open my_app/ and add below code to it.
from django.urls import path
from my_app import views

urlpatterns = [
    # ...
    path('fbv_update_view/<int:pk>', views.fbv_update_view, name='fbv_update_view'),
    path('cbv_update_view/<int:pk>', views.CBVUpdateView.as_view(), name='cbv_update_view'),
    # ...