Simple CRUD Web example using Django 1.10, Python 35, Sqlite Db

Django comes with its own concept of developing web application using Model of the Table as base.

Basic steps involved in creating a CRUD app in Django are as follows:-

1- Create an Django Web Application base folder structure. We are using Eclipse with PyDev. For more details refer to below site: https://shdhumale.wordpress.com/2017/03/03/simple-django-hello-world-programe-using-eclipse-python-3-5-and-django-1-10/
2- Create the Model class. This model class is responsible for creation of Table in our Database.
3- Create the View logic that we are planning to display to the end user
4- Declare and define the URLs which is going to map our view part. This url is resposible to divert the call to specific python class and html page depending on our relam or browser url.
5- Create the Templates where we put all our html file that we are planning to display to the end user.i.e. html file.

Step 1:- Creating an Django application. We can do this using CLI command i.e. ./manage.py startapp servers or use Eclipse process to create the Django Projects. Files marked in red colour will not be created by our eclipse plugin.

Step 2:- Add our newly created project entry in settings.py

INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'siddhucruddjango',
]

Step 3:- Create Model class.

This class represent our Database Table. Create Model.py class inside our project.

from django.db import models
from django.core.urlresolvers import reverse

class SiddhuModel(models.Model):
name = models.CharField(max_length=200)
address = models.CharField(max_length=200)
emailid = models.CharField(max_length=20)

def __unicode__(self):
return self.name

def get_absolute_url(self):
return reverse('siddhu_update', kwargs={'pk': self.pk})

In Django Primary key is mandatory to have in table. If we did not define it frame work will automatically create an ID field for the same in table for us. In above python we had define a class SiddhuModel. When we execute this class using below command we will see migration folder created inside our project with files like __init__.py and 0001_initial.py.

./manage.py makemigrations
./manage.py migrate

Try to analysis the code created inside 0001_initial.py.

operations = [
migrations.CreateModel(
name='SiddhuModel',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('name', models.CharField(max_length=200)),
('address', models.CharField(max_length=200)),
('emailid', models.CharField(max_length=20)),
],
),
Above code indicate when this files is executed it will create a table called siddhumodel with following four field. id, name, address and emailid.

As we are using SQLite as database, I prefer to use SQLite Studio to see the database and its table.

You can download SQLite from https://sqlitestudio.pl/index.rvt.

our model.py will create follwing table in our database.

Step 3:- Modify our View logic for displaying the data to the end users.

Create a views.py file inside our project and place following code. Note:- We are using Class-based views.

from django.http import HttpResponse
from django.views.generic import TemplateView,ListView
from django.views.generic.edit import CreateView, UpdateView, DeleteView
from django.core.urlresolvers import reverse_lazy

from siddhucruddjango.models import SiddhuModel

class SiddhuList(ListView):
model = SiddhuModel

class SiddhuInsert(CreateView):
model = SiddhuModel
success_url = reverse_lazy('siddhu_list')
fields = ['name', 'address', 'emailid']

class SiddhuUpdate(UpdateView):
model = SiddhuModel
success_url = reverse_lazy('siddhu_list')
fields = ['name', 'address', 'emailid']

class SiddhuDelete(DeleteView):
model = SiddhuModel
success_url = reverse_lazy('siddhu_list')

Step 4:- Modify URLS for navigations.

Change urls.py with below code.

from django.conf.urls import url
from django.contrib import admin

from siddhucruddjango import views

urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^$', views.SiddhuList.as_view(), name='siddhu_list'),
url(r'^insert$', views.SiddhuInsert.as_view(), name='siddhu_insert'),
url(r'^update/(?P\d+)$', views.SiddhuUpdate.as_view(), name='siddhu_update'),
url(r'^delete/(?P\d+)$', views.SiddhuDelete.as_view(), name='siddhu_delete'),
]

Step 5:- Develop UI HTML Part

Create a template folder inside our project. Create another folder with siddhucruddjango inside template and keep all our ui part files inside it.

and open the url the screen http://127.0.0.1:8000/

Click on Click to Create New Data link and follwing screen will be displayed

Fill the data and click on submit and check data is enter in our sqlite db.

Click on delete option and you will get following screen submit the button and check data is deleted from screen and databae.

Note:- For Function Based View use below code

1- urls.py 

from django.conf.urls import url
from django.contrib import admin

from siddhucruddjango import views

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^$', views.SiddhuList, name='siddhu_list'),
  url(r'^insert$', views.SiddhuInsert, name='siddhu_insert'),
  url(r'^update/(?P\d+)$', views.SiddhuUpdate, name='siddhu_update'),
  url(r'^delete/(?P\d+)$', views.SiddhuDelete, name='siddhu_delete'),
]

2- views.py

from django.shortcuts import render, redirect, get_object_or_404
from django.forms import ModelForm

from siddhucruddjango.models import SiddhuModel

class ServerForm(ModelForm):
    class Meta:
        model = SiddhuModel
        fields = ['name', 'address', 'emailid']

def SiddhuList(request, template_name='siddhucruddjango/SiddhuModel_list.html'):
    servers = SiddhuModel.objects.all()
    data = {}
    data['object_list'] = servers
    return render(request, template_name, data)

def SiddhuInsert(request, template_name='siddhucruddjango/SiddhuModel_form.html'):
    form = ServerForm(request.POST or None)
    if form.is_valid():
        form.save()
        return redirect('siddhu_list')
    return render(request, template_name, {'form':form})

def SiddhuUpdate(request, pk, template_name='siddhucruddjango/SiddhuModel_form.html'):
    server = get_object_or_404(SiddhuModel, pk=pk)
    form = ServerForm(request.POST or None, instance=server)
    if form.is_valid():
        form.save()
        return redirect('siddhu_list')
    return render(request, template_name, {'form':form})

def SiddhuDelete(request, pk, template_name='siddhucruddjango/SiddhuModel_confirm_delete.html'):
    server = get_object_or_404(SiddhuModel, pk=pk)    
    if request.method == 'POST':
        server.delete()
        return redirect('siddhu_list')
    return render(request, template_name, {'object':server})