Django Notes

ORM Notes

objects.all()
objects.all().count()
objects.filter(published=True).count()
objects.filter(published=True).exists()
objects.filter(published=True)[:2]
objects.filter(published=True).values('title','created')[:2]
objects.filter(published=True).order_by('created')
objects.filter(published=True).order_by('-created')

objects.filter(published=True, created__gt=datetime(2011,05,01))
objects.filter(published=True, created__lt=datetime(2011,05,01))
objects.filter(published=True, created__lt=datetime(2011,05,01)).count()
objects.filter(published=True, created__lt=datetime(2011,05,01)).order_by('id')
objects.filter(published=True, created__year=2011.order_by('id')
objects.filter(published=True, created__month=5, created__year=2011.order_by('id')

Print query

str(objects.filter(published=True, created__year=2011.order_by('id').query()))

Custom Query

objects.extra(select={'now':NOW()}).values('now')
objects.exta(select={'count':'SELECT COUNT(*) FROM table_name }).values('count')

objects.extra(where=['id=%s']),params=['3'])
Note = params prevent from sql injections 

Raw

objects.raw('SELECT * from table_name')[0].id

deep SQL

from django.db import connection
cursor = connection.cursor()
cursor.execute("SELECT * FROM tablename)
print cursor.fetchone()
print cursor.fetchall()

Signals

1 = post_save
2 = request_finshed
finshed single """
handlers.py
def request_finshed(sender,**kwargs):
  print "finshed",kwargs


{
form app import handelrs  #import the handlers file
models.py
from django.core.signals import request_finshed
request_finshed.connect(handlers,request_finshed)  ## connect to handler
}

model saved signal

handlers.py

def model_saved(sender,**kwargs):
  print "Saved", kwargs

models.py
from django.core.signals import post_save

post_save.connect(handler,model_saved , sender=Model)

Custom Signal

signals.py
from django.dispatcher import signal

signal_name = signal(providing_args['argname'])

import custom signal in the views.py

from appname import signals

signals.signalname.send(sender=ContactForm ,email=email)

import it in the model

from appname.signal import signalname

signalname.connect(handlers,signalname)

Sessions

add it to installed apps and middleware apps

set session

requst.session['session_vairable_name'] = True

check_session_exisit = request.session.get('session_vairable_name',False)

flat pages

settings.py  make sure it installed app and middle ware
then syncdb :) 
add pages from admin panel


create template inside templates/flatpages/default.html

{{ block content }}
  {{ flatpage.content }}
{{ endblock }}


by default u get free route 

setup custom route for flatpages with name to reuse it in the template

url(r'^about/$' ,'django.contrib.flatpages.views.flatpage' , kwargs('url': '/about/') , name="about_page")

in admin panel set the template path in advanced options

User Authentication
settings file

get sure of
installed app

auth
session
middleware
context processor

LOGIN_REDIRECT_URL = '/profile/'
LOGIN_URL = '/login/'

URLs for login

from django.contrib.auth.views import login,logout

url(r'profile/$','profile', name='homepage_profile')

url(r'login/$', login ,kwargs {'template_name': 'homepage/login.html', name='homepage_login'})
url(r'login/$', logout ', kwargs {'next_page': '/'}, name='homepage_login'})

protect action in views

from django.contrib.auth.decorates import login_required

@login_required

*template

{{ user }} # prints username

{ % if user.is_authenticated % }

UserProfile

create app called accounts

create app called accounts
  creat init file inside the app with auth module
  creat backends.py 
  from django.contrib.auth.backends import ModelBackend
  creat class inherit from modelbackend
  
  class MyModelBackend(ModelBackend)
      def authinticate(self,username None ,password None,)

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Comment *

Name *

Email *

Website

CAPTCHA Code *

Δ

This site uses Akismet to reduce spam. Learn how your comment data is processed.