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209 changes: 209 additions & 0 deletions content/postgresql-django.rst
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PostgreSql + Django
===================

:date: 2015-02-05 18:00
:tags: python, postresql, banco de dados
:category: Python, Banco de dados
:slug: postgresql-django
:author: Regis da Silva
:email: [email protected]
:github: rg3915
:summary: Esta é a parte 3 (de 3) da série de posts sobre PostgreSql...

Se você já leu o *Tutorial Postgresql* e *Postgresql + Python3*, este post é uma continuação. Aqui nós veremos usar PostgreSql no `Django <http://pythonclub.com.br/tutorial-django-17.html>`_.

Para quem já leu `Two Scoops of Django <http://twoscoopspress.com/products/two-scoops-of-django-1-6>`_ sabe que o `PyDanny <http://www.pydanny.com/>`_ recomenda fortemente o uso do `PostgreSQL <http://www.postgresql.org/>`_ em seus projetos.

Então vejamos aqui como configurar o Postgresql para ser usado no `Django <http://pythonclub.com.br/tutorial-django-17.html>`_.

Precisamos criar o banco manualmente
------------------------------------

Começando...

.. code-block:: bash

$ sudo su - postgres

Veja o prompt:

.. code-block:: bash

postgres@myuser:~$

Criando o banco

.. code-block:: bash

$ createdb mydb

Se existir o banco faça

.. code-block:: bash

$ dropdb mydb

e crie novamente. Para sair digite

.. code-block:: bash

$ exit

Django
------

Vamos criar um virtualenv e instalar o `psycopg2 <http://initd.org/psycopg/docs/install.html#use-a-python-package-manager>`_, além do django.

.. code-block:: bash

virtualenv -p /usr/bin/python3 teste
cd teste
source bin/activate
pip install psycopg2 django
pip freeze
pip freeze > requirements.txt

**Dica**: Para diminuir o caminho do prompt digite

.. code-block:: bash

$ PS1="(`basename \"$VIRTUAL_ENV\"`):/\W$ "

**Dica**:

.. code-block:: bash

vim ~/.bashrc +
alias manage='python $VIRTUAL_ENV/manage.py'

Com isto nós podemos usar apenas ``manage`` ao invés de ``python manage.py``.

Criando o projeto
^^^^^^^^^^^^^^^^^

.. code-block:: bash

django-admin.py startproject myproject .
cd myproject
python ../manage.py startapp core

**Edite o settings.py**

.. code-block:: python

DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.path.join(BASE_DIR, 'mydb'),
'USER': 'myuser',
'PASSWORD': 'mypassword',
'HOST': '127.0.0.1',
'PORT': '', # 8000 is default
}
}

**Rode a aplicação**

.. code-block:: bash

python manage.py migrate
python manage.py runserver

http://127.0.0.1:8000/ ou http://localhost:8000/

**Edite o models.py**

.. code-block:: python

from django.db import models
from django.utils.translation import ugettext_lazy as _


class Person(models.Model):
name = models.CharField(_('Nome'), max_length=50)
email = models.EmailField(_('e-mail'), max_length=30, unique=True)
age = models.IntegerField(_('Idade'))
active = models.BooleanField(_('Ativo'), default=True)
created_at = models.DateTimeField(
_('Criado em'), auto_now_add=True, auto_now=False)

class Meta:
ordering = ['name']
verbose_name = "pessoa"
verbose_name_plural = "pessoas"

def __str__(self):
return self.name

Leia mais em

`Tutorial Django 1.7 <http://pythonclub.com.br/tutorial-django-17.html>`_

`Como criar um site com formulário e lista em 30 minutos? <http://pythonclub.com.br/criar-site-com-form-lista-30-min.html>`_

**Edite o settings.py** novamente

Em *INSTALLED_APPS* insira a app *core*.

.. code-block:: python

INSTALLED_APPS = (
...
'myproject.core',
)

**Faça um migrate**

.. code-block:: bash

python manage.py makemigrations core
python manage.py migrate

Um pouco de shell
^^^^^^^^^^^^^^^^^

.. code-block:: bash

python manage.py shell
Python 3.4.0 (default, Apr 11 2014, 13:05:18)
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>>



Serve para manipular a app pelo **terminal**.

.. code-block:: python

>>> from myproject.core.models import Person
>>> p = Person.objects.create(name='Regis',email='[email protected]',age=35)
>>> p.id
>>> p.name
>>> p.email
>>> p.age
>>> p.active
>>> p.created_at
>>> p = Person.objects.create(name='Xavier',email='[email protected]',age=66,active=False)
>>> persons = Person.objects.all().values()
>>> for person in persons: print(person)
>>> exit()

Leia mais em

*Tutorial PostgreSql*

*PostgreSql + Python3*

`Tutorial Django 1.7 <http://pythonclub.com.br/tutorial-django-17.html>`_

`Como criar um site com formulário e lista em 30 minutos? <http://pythonclub.com.br/criar-site-com-form-lista-30-min.html>`_

`How To Install and Configure Django with Postgres, Nginx, and Gunicorn <https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-django-with-postgres-nginx-and-gunicorn>`_

http://www.postgresql.org/docs/9.4/static/tutorial-createdb.html

http://www.postgresql.org/docs/9.4/static/index.html

http://www.postgresql.org/docs/9.4/static/tutorial-sql.html
123 changes: 123 additions & 0 deletions content/postgresql-python3.rst
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PostgreSql + Python3
====================

:date: 2015-02-05 13:00
:tags: python, postresql, banco de dados
:category: Python, Banco de dados
:slug: postgresql-python3
:author: Regis da Silva
:email: [email protected]
:github: rg3915
:summary: Esta é a parte 2 (de 3) da série de posts sobre PostgreSql...

Se você já leu o *Tutorial Postgresql* este post é uma continuação. Aqui nós veremos como manipular um banco de dados PostgreSql no Python3.

Além da instalação mostrada no primeiro post precisaremos de

.. code-block:: bash

$ sudo apt-get install python-psycopg2 # para python2
# ou
$ sudo apt-get install python3-psycopg2 # para python3

Começando...

.. code-block:: bash

$ sudo su - postgres

Veja o prompt:

.. code-block:: bash

postgres@myuser:~$

Criando o banco

.. code-block:: bash

$ createdb mydb

Se existir o banco faça

.. code-block:: bash

$ dropdb mydb

e crie novamente. Para sair digite

.. code-block:: bash

$ exit

Abra o python3.

.. code-block:: bash

$ python3
Python 3.4.0 (default, Apr 11 2014, 13:05:18)
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>

Importe o psycopg2

.. code-block:: python

>>> import psycopg2

Conectando a um banco de dados existente

.. code-block:: python

>>> conn = psycopg2.connect("dbname=mydb user=myuser")

Abrindo um cursor para manipular o banco

.. code-block:: python

>>> cur = conn.cursor()

Criando uma nova tabela

.. code-block:: python

>>> cur.execute("CREATE TABLE person (id serial PRIMARY KEY, name text, age integer);")

Inserindo dados.O Psycopg faz a conversão correta. Não mais injeção SQL.

.. code-block:: python

>>> cur.execute("INSERT INTO person (name, age) VALUES (%s, %s)",("O'Relly", 60))
>>> cur.execute("INSERT INTO person (name, age) VALUES (%s, %s)",('Regis', 35))

Grava as alterações no banco

.. code-block:: python

>>> conn.commit()

# Select

.. code-block:: python

>>> cur.execute("SELECT * FROM person;")
>>> cur.fetchall()

Fecha a comunicação com o banco

.. code-block:: python

>>> cur.close()
>>> conn.close()
>>> exit()

Leia também

*Tutorial PostgreSql*

*PostgreSql + Django*

http://initd.org/psycopg/docs/

http://initd.org/psycopg/docs/usage.html
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