本系列教程适用于Django入门，文章翻译自官方英文文档，在官方文档的基础上进行web开发和python语言学习的扩展。下面就开始了。请指教。
设计model
web开发的基础是数据。Django中可以不直接对数据库进行操作，使用ORM对数据进行描述。下面是一个入门例子：
from django.db import models
class Reporter(models.Model):
full_name = models.CharField(max_length=70)
def __str__(self):
return self.full_name
class Article(models.Model):
pub_date = models.DateField()
headline = models.CharField(max_length=200)
content = models.TextField()
reporter = models.ForeignKey(Reporter)
def __str__(self):
return self.headline
本例中定义了两个集成自models.Model的类 Reporter和Article。
安装
python manage.py migrate
D:\proj\mysite>python manage.py migrate
Operations to perform:
Apply all migrations: admin, contenttypes, polls, auth, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying polls.0001_initial... OK
Applying sessions.0001_initial... OK
migrate命令检查所有的models，创建在数据库中没有建立。
1. python manage.py makemigrations
2. python manage.py migrate
创建新的model的时候，分别执行上面的步骤。把数据库更新。
自由的api
D:\proj\mysite>python manage.py shell
Python 2.7.8 (default, Jun 30 2014, 16:03:49) [MSC v.1500 32 bit (Intel)] on win
32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from news.models import Reporter,Article
>>> Reporter.objects.all()
[]
>>> r = Reporter(full_name="John Smith")
>>> r.save()
>>> Reporter.objects.all()
[<Reporter: John Smith>]
>>> r.id
1L
>>> r.full_name
'John Smith'
>>> Reporter.objects.get(id=1)
<Reporter: John Smith>
>>> Reporter.objects.get(full_name__startswith='John')
<Reporter: John Smith>
>>> Reporter.objects.get(id=2)
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "C:\Python27\lib\site-packages\django-1.7.1-py2.7.egg\django\db\models\ma
nager.py", line 92, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "C:\Python27\lib\site-packages\django-1.7.1-py2.7.egg\django\db\models\qu
ery.py", line 357, in get
self.model._meta.object_name)
DoesNotExist: Reporter matching query does not exist.
>>> from datetime import date
>>> a = Article(pub_date=date.today(), headline="Django is cool", content="Yeah"
, reporter=r)
>>> a.save()
api的学习需要看相关文档，了解Django的ORM如何对数据库进行操作。
看数据库的时候发现了一个外键的问题：
- 外键关联的是一个对象，自动生成的外键名称会在关联的对象的名称后面加上个"_id"作为字段名称
- 默认情况下，外键会自动创建索引，会自动做级联删除，默认的外键是
Admin接口
不仅是一个基架，更是一个整体。Django能创建一个专业的管理Model对象的接口。
编辑mysite/news/admin.py文件
from django.contrib import admin
from . import models
admin.site.register(models.Article)
设计URLS
创建一个叫URLconf的python module。设计一个urls.py
from django.conf.urls import patterns
from . import views
urlpatterns = patterns('',
(r'^articles/(\d{4})/$', views.year_archive),
(r'^articles/(\d{4})/(\d{2})/$', views.month_archive),
(r'^articles/(\d{4})/(\d{2})/(\d+)/$', views.archive_detail),
)
设计Views
每个view负责返回一个HttpResponse object或者返回一个404异常。
一个简单的例子。
from django.shortcuts import render
from .models import Article
def year_archive(request, year):
a_list = Article.objects.all()
context = {'year':year, 'article_list':a_list}
return render(request, 'news/year_archive.html', context)
获取数据，把数据渲染到模板上。
