Quick Start with Django installations on Ubuntu

Django installations on Ubuntu.md

Django installations on Ubuntu

Installing Python in system

First step install dependencies.

sudo apt-get install git python-setuptools python-pip python-dev \
&& sudo apt-get install python3-pip python3-dev virtualenv

then install local envirement of Django project.

cd /to/your/project
virtualenv --nosite-packages env

pip install --upgrade pip setuptools wheel

activate your local envirement:

source env/bin/activate or . env/bin/activate then install Django:

easy_install Django or pip install Django.

to getting started check Django availabel commands

django-admin.py

start new project called project1 by

django-admin.py startproject project1

then run the project1

python manage.py runserver

to deactivate local envirement

deactivate # to deactivate envirement

reactive your local envirement then start new app called article

python manage.py startapp article # (to create article model folder)

Setting up django database

syncdb command to add tables of app models to your database

for previous version 1.6>= django

python manage.py syncdb           # (add tables synchronounslly)
python manage.py sql article      # (to see SQL command for creating article table)
python manage.py reset article    # (to delete article table)

the most amazing features that integrated in Django is shell connect to test your scripts depend on project and local envirement.

python manage.py shell            # to add object to article table in terminal

inside the shell you can execute some script depend on project.

>>> from article.models import article
>>> Article.objects.all()
[]
>>> from django.utils import timezone
>>> a = Article(title="Test 1", body="blah", pub_date=timezone.now(), likes=0)
>>> a
<Article: Article object>
>>> a.save()
>>> a.id
1

if you have assets file you can collect them in your static directory.

python manage.py collectstatic    # This command to copy your assets files for admin to static folder in your project

Setting up mysql database

in this section we will learn how to integrate between Django and its MySQL database

to connect to mysql with django you need to install these dependencies.

sudo apt-get install build-essential python-dev python3-dev libmysqlclient-dev python-mysqldb libssl-dev # Debian / Ubuntu
sudo yum install python-devel mysql-devel # Red Hat / CentOS
brew install mysql-connector-c # macOS (Homebrew) (Currently, it has bug. See below)

after that you should install this library for global and local envirement.

pip install mysqlclient

finally you may synchronous your database without problem. Django 1.6 and lower

python manage.py syncdb 

Django 1.7 and higher

python manage.py migrate --run-syncdb

PostgreSQL

Setting up PostgreSQL database

install postgre dependencies

sudo apt-get update
sudo apt-get install libpq-dev postgresql-client postgresql-client-common
sudo apt-get install python-psycopg2 python3-psycopg2
sudo apt-get install postgresql postgresql-contrib

setting up postgres user and database

sudo passwd postgres
su - postgres
psql -d template1 -c "ALTER USER postgres WITH PASSWORD 'newpassword';"

or

sudo -u postgres psql

create role anyuser with password '123456';
alter role anyuser createrole login;
alter role anyuser createrole superuser;

creating database by:

create database anydb;
grant all privileges on database anydb to anyuser;
\q

to delete database by:

drop database anydb;

Transferring databases

Export PostgreSQL Database

pg_dump -U username dbname > dbexport.pgsql

Import PosgreSQL Database

psql -U username dbname < dbexport.pgsql

Test Connection to Database

Testing conntion to database in bash script

pg_isready -d <db_name> -h <host_name> -p <port_number> -U <db_user>

Change Database Owner

ALTER DATABASE target_database OWNER TO new_onwer;

Change Table Owner

\c target_database
ALTER TABLE target_table_name OWNER TO new_onwer;

According to: PostgreSQL Tutorial

Set User Privileges on DB

\c selected_db;
REVOKE ALL ON ALL TABLES FROM USER user;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO user;
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA public to user;
GRANT USAGE, SELECT ON ALL SEQUENCES IN SCHEMA public TO user;

Check database max connection limit on DB

select  * from
(select count(*) used from pg_stat_activity) q1,
(select setting::int res_for_super from pg_settings where name=$$superuser_reserved_connections$$) q2,
(select setting::int max_conn from pg_settings where name=$$max_connections$$) q3;

source: here

Check database connections on DB

SELECT client_addr,COUNT(*) FROM pg_stat_activity GROUP BY client_addr ORDER BY 2 DESC;

To cancel SQL query in PostgreSQL use:

SELECT pg_cancel_backend(pid) FROM pg_stat_activity WHERE state = 'active' and pid <> pg_backend_pid();

source: here

Adding new User and grant to sudo

sudo adduser newuser
sudo gpasswd -a newuser sudo
su - newuser

Setting up xml and json api modules

working with xml and json api

pip install django-tastypie
pip install defusedxml "lxml>=3" 

if it does not work you may do the following commands

sudo dpkg --configure -a
sudo apt-get install libxml2-dev libxslt1-dev python-dev
sudo apt-get install python-lxml

Installing South (If you are using new version skip it)

South Depricated in Django 1.7 and higher

database migrations and upating schema using south

pip install south
chmod +x manage.py
./manage.py
./manage.py schemamigration article --initial

after that the following command will be available

./manage.py migrate article

the following command is used for modify any change has happen in Article model

./manage.py schemamigration article --auto

if you want to delete or undo the migration we can go back to the preview migration like the following command

./manage.py migrate article 0002 # if the last one was 0003

if I want to go back to the version 0003

./manage.py schemamigration article
./manage.py migrate article --fake
./manage.py datamigration article convert_names

Setting up haystack for django

working with haystack and Whoosh.

Full text search using haystack and Whoosh.

pip install whoosh django-haystack
./manage.py rebuild_index

Setting up notifications

create notification app example filtering data by user and sending notification

./manage.py startapp notification
./manage.py schemamigration notification --initial
./manage.py migrate

Twitter Bootstrap with Django

using Twitter Bootstrap in Django Reusing apps and using twitter bootstrap

pip install django south django-bootstrap-toolkit

Django load & dump data

In this case I am using json format, when you backup whole database by using dumpdata command, it will backup all the database tables.

• If you use this database dump to load the fresh database(in another django project), it can be causes IntegrityError (If you loaddata in same database it works fine)
• To fix this problem, make sure to backup the database by excluding contenttypes and auth.permissions tables

./manage.py dumpdata --exclude auth.permission --exclude contenttypes > db.json

Now you can use loaddata command with a fresh database safely

./manage.py loaddata db.json

Delete Sessions table

This is used to remove user's sessions on running django project, log into interactive shell:

python manage.py shell

then

>>> from django.contrib.sessions.models import Session
>>> Session.objects.all().delete()
(15428, {'sessions.Session': 15428})

Conclusion

This is the simplest and fasted way to learn Django very quickly, this is tutorial good for people has the basic knowledge in Python2 and Python3, and good for who is familier with Terminal and Unix envirement.