转载

Django快速开发之投票系统

https://docs.djangoproject.com/en/1.8/intro/tutorial01/

参考官网文档，创建投票系统。

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Windows 7/10

Python 2.7.10

Django 1.8.2

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1、创建项目（ mysite ）与应用（ polls ）

D:/pydj> django-admin.py startproject mysite

D:/pydj>cd mysite

D:/pydj/mysite> python manage.py startapp polls

添加到 setting.py

# Application definition  INSTALLED_APPS = (  'django.contrib.admin',  'django.contrib.auth',  'django.contrib.contenttypes',  'django.contrib.sessions',  'django.contrib.messages',  'django.contrib.staticfiles',  'polls', )

最终哪个目录结构：

Django快速开发之投票系统

2、创建模型（即数据库）

一般 web 开发先设计数据库，数据库设计好了，项目就完了大半了，可见数据库的重要性。打开 polls/models.py 编写如下：

# coding=utf-8 from django.db import models # Create your models here. # 问题 class Question(models.Model):  question_text = models.CharField(max_length=200)  pub_date = models.DateTimeField('date published')  def __unicode__(self):   return self.question_text # 选择 class Choice(models.Model):  question = models.ForeignKey(Question)  choice_text = models.CharField(max_length=200)  votes = models.IntegerField(default=0)  def __unicode__(self):   return self.choice_text

执行数据库表生成与同步。

D:/pydj/mysite>python manage.py makemigrations polls Migrations for 'polls':   0001_initial.py:     - Create model Question     - Create model Choice     - Add field question to choice  D:/pydj/mysite>python manage.py syncdb …… You have installed Django's auth system, and don't have any superusers defined. Would you like to create one now? (yes/no): yes Username (leave blank to use 'fnngj'):    用户名（默认当前系统用户名） Email address: fnngj@126.com     邮箱地址 Password:     密码 Password (again):    重复密码 Superuser created successfully.

3、admin 管理

django 提供了强大的后台管理，对于 web 应用来说，后台必不可少，例如，当前投票系统，如何添加问题与问题选项？直接操作数据库添加，显然麻烦，不方便，也不安全。所以，管理后台就可以完成这样的工作。

打开 polls/admin.py 文件，编写如下内容：

from django.contrib import admin from .models import Question, Choice # Register your models here. class ChoiceInline(admin.TabularInline):  model = Choice  extra = 3 class QuestionAdmin(admin.ModelAdmin):  fieldsets = [   (None,      {'fields': ['question_text']}),   ('Date information', {'fields': ['pub_date'], 'classes': ['collapse']}),  ]  inlines = [ChoiceInline]  list_display = ('question_text', 'pub_date') admin.site.register(Choice) admin.site.register(Question, QuestionAdmin)

当前脚本的作用就是将模型（数据库表）交由 admin 后台管理。

运行 web 容器：

D:/pydj/mysite>python manage.py runserver Performing system checks...  System check identified no issues (0 silenced). October 05, 2015 - 13:08:12 Django version 1.8.2, using settings 'mysite.settings' Starting development server at http://127.0.0.1:8000/ Quit the server with CTRL-BREAK.

登录后台： http://127.0.0.1:8000/admin

登录密码就是在执行数据库同步时设置的用户名和密码。

Django快速开发之投票系统

点击“ add ”添加问题。

Django快速开发之投票系统

4 、编写视图

视图起着承前启后的作用，前是指前端页面，后是指后台数据库。将数据库表中的内容查询出来显示到页面上。

编写 polls/views.py 文件：

# coding=utf-8 from django.shortcuts import render, get_object_or_404 from django.http import HttpResponseRedirect, HttpResponse from django.core.urlresolvers import reverse from .models import Question, Choice # Create your views here. # 首页展示所有问题 def index(request):  # latest_question_list2 = Question.objects.order_by('-pub_data')[:2]  latest_question_list = Question.objects.all()  context = {'latest_question_list': latest_question_list}  return render(request, 'polls/index.html', context) # 查看所有问题 def detail(request, question_id):  question = get_object_or_404(Question, pk=question_id)  return render(request, 'polls/detail.html', {'question': question}) # 查看投票结果 def results(request, question_id):  question = get_object_or_404(Question, pk=question_id)  return render(request, 'polls/results.html', {'question': question}) # 选择投票 def vote(request, question_id):  p = get_object_or_404(Question, pk=question_id)  try:   selected_choice = p.choice_set.get(pk=request.POST['choice'])  except (KeyError, Choice.DoesNotExist):   # Redisplay the question voting form.   return render(request, 'polls/detail.html', {    'question': p,    'error_message': "You didn't select a choice.",   })  else:   selected_choice.votes += 1   selected_choice.save()   # Always return an HttpResponseRedirect after successfully dealing   # with POST data. This prevents data from being posted twice if a   # user hits the Back button.   return HttpResponseRedirect(reverse('polls:results', args=(p.id,)))

5 、配置 url

url 是一个请求配置文件，页面中的请求转交给由哪个函数处理，由该文件决定。

首先配置 polls/urls.py( 该文件需要创建 )

from django.conf.urls import url from . import views urlpatterns = [  # ex : /polls/  url(r'^$', views.index, name='index'),  # ex : /polls/5/  url(r'^(?P<question_id>[0-9]+)/$', views.detail, name='detail'),  # ex : /polls/5/results/  url(r'^(?P<question_id>[0-9]+)/results/$', views.results, name='results'),  # ex : /polls/5/vote  url(r'^(?P<question_id>[0-9]+)/vote/$', views.vote, name='vote'), ]

接着，编辑 mysite/urls.py 文件。

from django.conf.urls import include, url from django.contrib import admin  urlpatterns = [     url(r'^polls/', include('polls.urls', namespace="polls")),     url(r'^admin/', include(admin.site.urls)), ]

6 、创建模板

模板就是前端页面，用来将数据显示到 web 页面上。

首先创建 polls/templates/polls/ 目录，分别在该目录下创建 index.html 、 detail.html 和 results.html 文件。

index.html

{% if latest_question_list %}  <ul>  {% for question in latest_question_list %}   <li><a href="{% url 'polls:detail' question.id %}">{{ question.question_text }}</a></li>  {% endfor %}  </ul> {% else %}  <p>No polls are available.</p> {% endif %}

detail.html

<h1>{{ question.question_text }}</h1>  {% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %}  <form action="{% url 'polls:vote' question.id %}" method="post"> {% csrf_token %} {% for choice in question.choice_set.all %}     <input type="radio" name="choice" id="choice{{ forloop.counter }}" value="{{ choice.id }}" />     <label for="choice{{ forloop.counter }}">{{ choice.choice_text }}</label><br /> {% endfor %} <input type="submit" value="Vote" /> </form>

results.html

<h1>{{ question.question_text }}</h1>  <ul> {% for choice in question.choice_set.all %}     <li>{{ choice.choice_text }} -- {{ choice.votes }} vote{{ choice.votes|pluralize }}</li> {% endfor %} </ul>  <a href="{% url 'polls:detail' question.id %}">Vote again?</a>