Django 1.6.1 logs part 01 ( install, access to PostgreSQL, write models )

[ install Django on Ubuntu 13.10 ]

# apt-get install python-setuptools # easy_install django

# python Python 2.7.5+ (default, Sep 19 2013, 13:48:49) [GCC 4.8.1] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import django >>> django.get_version() '1.6.1' >>>

start

# mkdir Django_works # cd Django_works/ # django-admin.py startproject example # cd example/ # python manage.py runserver 8080 Validating models... 0 errors found January 20, 2014 - 09:00:15 Django version 1.6.1, using settings 'example.settings' Starting development server at http://127.0.0.1:8080/ Quit the server with CONTROL-C.

access to http:// IP:8080

[ access to PostgreSQL ]

Reference

http://www.pythoncentral.io/writing-your-first-python-django-application/

create a project

# django-admin.py startproject myblog # cd myblog

install PostgreSQL

# apt-get install postgresql # apt-get install postgresql-server-dev-9.1 # apt-get install postgresql-client postgresql-client-common # /etc/init.d/postgresql status 9.1/main (port 5432): online

Create a DB

# su postgres $ psql psql (9.1.11) Type "help" for help. postgres=# CREATE USER foo01 WITH PASSWORD 'foo01'; CREATE ROLE postgres=# CREATE DATABASE myblog; CREATE DATABASE postgres=# GRANT ALL PRIVILEGES ON DATABASE myblog TO foo01; GRANT postgres=# \q  <- Ctrl + D

install PostgreSQL driver.

# easy_install psycopg2

edit mublog/settings.py to access PostgreSQL.

DATABASES = {    'default': { #        'ENGINE': 'django.db.backends.sqlite3', #        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),        'ENGINE': 'django.db.backends.postgresql_psycopg2',        'NAME': 'myblog',        'USER': 'foo01',        'PASSWORD': 'foo01',        'HOST': 'localhost',        'POSRT': '',    } }

initialize DB

# python manage.py syncdb Creating tables ... Creating table django_admin_log Creating table auth_permission Creating table auth_group_permissions Creating table auth_group Creating table auth_user_groups Creating table auth_user_user_permissions Creating table auth_user Creating table django_content_type Creating table django_session You just installed Django's auth system, which means you don't have any superusers defined. Would you like to create one now? (yes/no): yes Username (leave blank to use 'root'): Email address: Password: Password (again): Superuser created successfully. Installing custom SQL ... Installing indexes ... Installed 0 object(s) from 0 fixture(s)

# python manage.py shell >>> from django.contrib.auth.models import User >>> User.objects.all() [<User: root>] >>> exit

[ write models ]

Reference

http://www.pythoncentral.io/writing-models-for-your-first-python-django-application/

create an App called blog in myblog project.

python manage.py startapp blog

create a models.

# cat myblog/myblog.py from django.db import models class Post(models.Model):    content = models.CharField(max_length=256)    created_at = models.DateTimeField('Datetime created') class Comment(models.Model):    post = models.ForeignKey(Post)    message = models.TextField()    created_at = models.DateTimeField('Datetime created')

edit myblog/settings.py

INSTALLED_APPS = (    'django.contrib.admin',    'django.contrib.auth',    'django.contrib.contenttypes',    'django.contrib.sessions',    'django.contrib.messages',    'django.contrib.staticfiles',    'blog', )

check the DB command

# python manage.py sql blog BEGIN; CREATE TABLE "blog_post" (    "id" serial NOT NULL PRIMARY KEY,    "content" varchar(256) NOT NULL,    "created_at" timestamp with time zone NOT NULL ) ; CREATE TABLE "blog_comment" (    "id" serial NOT NULL PRIMARY KEY,    "post_id" integer NOT NULL REFERENCES "blog_post" ("id") DEFERRABLE INITIALLY DEFERRED,    "message" text NOT NULL,    "created_at" timestamp with time zone NOT NULL ) ; COMMIT;

creat the DB.

# python manage.py syncdb Creating tables ... Creating table blog_post Creating table blog_comment Installing custom SQL ... Installing indexes ... Installed 0 object(s) from 0 fixture(s)

python interactive shell

# python manage.py shell >>> from blog import models >>> dir() ['__builtins__', 'models'] >>> dir(models) ['Comment', 'Post', '__builtins__', '__doc__', '__file__', '__name__', '__package__', 'models'] >>> dir(models.Comment) ['DoesNotExist', 'MultipleObjectsReturned', '__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__getattribute__', '__hash__', '__init__', u'__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_base_manager', '_default_manager', '_deferred', '_do_insert', '_do_update', '_get_FIELD_display', '_get_next_or_previous_by_FIELD', '_get_next_or_previous_in_order', '_get_pk_val', '_get_unique_checks', '_meta', '_perform_date_checks', '_perform_unique_checks', '_save_parents', '_save_table', '_set_pk_val', 'clean', 'clean_fields', 'date_error_message', 'delete', 'full_clean', 'get_next_by_created_at', 'get_previous_by_created_at', 'objects', 'pk', 'post', 'prepare_database_save', 'save', 'save_base', 'serializable_value', 'unique_error_message', 'validate_unique'] >>>

Post object

>>> from django.utils import timezone >>> p = models.Post(content='Django is awesome.', created_at=timezone.now()) >>> p <Post: Post object> >>> p.created_at datetime.datetime(2014, 1, 21, 5, 19, 22, 790222, tzinfo=<UTC>) >>> models.Post.objects.all() [] >>> p.save() >>> models.Post.objects.all() [<Post: Post object>] >>> p.id 1 >>> p2 = m.Post(content='Pythoncentral is also awesome.', created_at=timezone.now()) >>> p2.save() >>> models.Post.objects.all() [<Post: Post object>, <Post: Post object>] >>> >>> models.Post.objects.all()[0].id 1 >>> models.Post.objects.all()[1].id 2

Comment Object

>>> dir(models.Comment) ['DoesNotExist', 'MultipleObjectsReturned', '__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__getattribute__', '__hash__', '__init__', u'__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_base_manager', '_default_manager', '_deferred', '_do_insert', '_do_update', '_get_FIELD_display', '_get_next_or_previous_by_FIELD', '_get_next_or_previous_in_order', '_get_pk_val', '_get_unique_checks', '_meta', '_perform_date_checks', '_perform_unique_checks', '_save_parents', '_save_table', '_set_pk_val', 'clean', 'clean_fields', 'date_error_message', 'delete', 'full_clean', 'get_next_by_created_at', 'get_previous_by_created_at', 'objects', 'pk', 'post', 'prepare_database_save', 'save', 'save_base', 'serializable_value', 'unique_error_message', 'validate_unique'] >>> c = models.Comment(message='This is a comment for p', created_at=timezone.no w())

class Comment(models.Model):

   post = models.ForeignKey(Post)

>>> p <Post: Post object> >>> c.post = p  <- post = models.ForeignKey(Post) >>> c.post <Post: Post object> >>> p.comment_set.all() [] >>> c.save() >>> p.comment_set.all() [<Comment: Comment object>]

Retrieve

>>> p.comment_set.filter(created_at__year=2014) [<Comment: Comment object>] >>> p.comment_set.filter(message__startswith='This is a') [<Comment: Comment object>]