Django 特点强大的数据库功能 用python的类继承，几行代码就可以拥有一个丰富，动态的数据库操作接口（API），如果需要你也能执行SQL语句自带的强大的后台功能 几行简单的代码就让你的网站拥有一个强大的后台，轻松管理你的内容！优雅的网址 用正则匹配网址，传递到对应函数，随意定义，如你所想！模板系统 强大，易扩展的模板系统，设计简易，代码，样式分开设计，更容易管理。缓存系统 与memcached或其它的缓存系统联用，更出色的表现，更快的加载速度。国际化 完全支持多语言应用，允许你定义翻译的字符，轻松翻译成不同国家的语言。Django 全貌一览urls.py 网址入口，关联到对应的views.py中的一个函数（或者generic类），访问网址就对应一个函数。views.py 处理用户发出的请求，从urls.py中对应过来, 通过渲染templates中的网页可以将显示内容，比如登陆后的用户名，用户请求的数据，输出到网页。models.py 与数据库操作相关，存入或读取数据时用到这个，当然用不到数据库的时候 你可以不使用。forms.py 表单，用户在浏览器上输入数据提交，对数据的验证工作以及输入框的生成等工作，当然你也可以不使用。templates 文件夹 views.py 中的函数渲染templates中的Html模板，得到动态内容的网页，当然可以用缓存来提高速度。admin.py 后台，可以用很少量的代码就拥有一个强大的后台。settings.py Django 的设置，配置文件，比如 DEBUG 的开关，静态文件的位置等。Django 基本命令新建 项目 $ django-admin startproject mysite新建 app $ python manage.py startapp blog 一般一个项目有多个app, 当然通用的app也可以在多个项目中使用。同步数据库 $ python manage.py migrate使用开发服务器 $ python manage.py runserver [port]清空数据库 $ python manage.py flush创建超级管理员 $ python manage.py createsuperuser导出数据 $ python manage.py dumpdata blog > blog.json导入数据 $ python manage.py loaddata blog.json项目环境终端 $ python manage.py shell数据库命令行 $ python manage.py dbshell查看更多命令 $ python manage.py
创建一个简单例子的流程
环境：windows7 + python3.4 + django1.8
====> Creating a project $ django-admin startproject mysite $ cd mysite====> Database setup $ edit mysite\settings.py
DATABASES = { 'default': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': os.path.join(BASE_DIR, 'db.sqlite3'), } }$ python manage.py migrate====> The development server (http://127.0.0.1:800) $ python manage.py runserver====> Creating models $ python manage.py startapp polls $ edit polls\models.py
from django.db import models class Question(models.Model): question_text = models.CharField(max_length=200) pub_date = models.DateTimeField('date published') class Choice(models.Model): question = models.ForeignKey(Question) choice_text = models.CharField(max_length=200) votes = models.IntegerField(default=0)====> Activating models $ edit mysite\settings.py
INSTALLED_APPS = ( 'django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.messages', 'django.contrib.staticfiles', 'polls', )$ python manage.py makemigrations polls $ python manage.py sqlmigrate polls 0001 $ python manage.py migrate【Remember the three-step guide to making model changes: Change your models (in models.py). Run python manage.py makemigrations to create migrations for those changes Run python manage.py migrate to apply those changes to the database.】====> Playing with the API $ python manage.py shell
>>> from polls.models import Question, Choice>>> >>> Question.objects.all() []>>> >>> from django.utils import timezone>>> >>> q = Question(question_text="What's new?", pub_date=timezone.now()) >>> q.save()>>> >>> q.id 1 >>> q.question_text "What's new?" >>> q.pub_date datetime.datetime(2012, 2, 26, 13, 0, 0, 775217, tzinfo=<UTC>)>>> >>> q.question_text = "What's up?" >>> q.save()>>> >>> Question.objects.all() [<Question: Question object>]
====> Change models.py $ edit polls\models.py
import datetime from django.db import models from django.utils import timezone class Question(models.Model): # ... def __str__(self): # __unicode__ on Python 2 return self.question_text def was_published_recently(self): return self.pub_date >= timezone.now() - datetime.timedelta(days=1) class Choice(models.Model): # ... def __str__(self): # __unicode__ on Python 2 return self.choice_text
====> Play the API again
$ python manage.py shell
>>> from polls.models import Question, Choice>>> >>> Question.objects.all() [<Question: What's up?>]>>> >>> Question.objects.filter(id=1) [<Question: What's up?>]>>>>>> Question.objects.filter(question_text__startswith='What') [<Question: What's up?>] >>>>>> from django.utils import timezone>>> >>> current_year = timezone.now().year >>> Question.objects.get(pub_date__year=current_year) <Question: What's up?> >>>>>> Question.objects.get(id=2) Traceback (most recent call last): ... DoesNotExist: Question matching query does not exist. >>> Question.objects.get(pk=1) <Question: What's up?> >>>>>> q = Question.objects.get(pk=1) >>> q.was_published_recently() True >>> q = Question.objects.get(pk=1) >>>>>>>>> q.choice_set.all() [] >>> q.choice_set.create(choice_text='Not much', votes=0) <Choice: Not much>>>> >>> q.choice_set.create(choice_text='The sky', votes=0) <Choice: The sky>>>>>>> >>> c = q.choice_set.create(choice_text='Just hacking again', votes=0) >>> c.question <Question: What's up?> >>>>>> q.choice_set.all() [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>] >>> q.choice_set.count() 3>>> >>> Choice.objects.filter(question__pub_date__year=current_year) [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>]>>> >>> c = q.choice_set.filter(choice_text__startswith='Just hacking') >>> c.delete()
转载于:https://www.cnblogs.com/hhh5460/p/4458879.html
