Django + mysql 快速搭建簡單web投票系統

瞭解學習pyhton web的簡單demo

1. 安裝Django， 安裝pyhton 自行百度

2. 執行命令建立project  django-admin.py startproject mysite

3. 執行命令建立app python manage.py startapp polls

目錄結構：   polls/templates/polls 目錄  和  polls/admin.py 都是本身手動建立的。 

 

4. 編輯setting.py 添加app  polls  同時打開admin

INSTALLED_APPS = (
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.sites',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'polls',
    # Uncomment the next line to enable the admin:
    'django.contrib.admin',
    # Uncomment the next line to enable admin documentation:
    # 'django.contrib.admindocs',
)

 

5. 編輯setting.py 添加數據庫鏈接信息

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql', # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
        'NAME': 'polls',                      # Or path to database file if using sqlite3.
        'USER': 'root',                      # Not used with sqlite3.
        'PASSWORD': '123',                  # Not used with sqlite3.
        'HOST': '',                      # Set to empty string for localhost. Not used with sqlite3.
        'PORT': '',                      # Set to empty string for default. Not used with sqlite3.
    }
}

　　

6. 建立Modle模型 ：

# coding=utf-8


from django.db import models

# Create your models here.
class Question(models.Model):
    question_text = models.CharField(max_length=200)
    pub_date = models.DateTimeField('date published')

    def __unicode__(self):
        return self.question_text


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

7.  執行數據庫同步  （ORM）自動根據model定義建立表接口 （我這裏使用的mysql）

首先建立數據庫  

create database polls;

而後執行命令：  

python manage.py syncdb

 

8. 檢查數據庫中表的建立： 

use polls

show tables

 

9. 建立admin.py

# coding=utf-8


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)

　　

10. 啓動應用

python manage.py runserver

登陸後臺：http://127.0.0.1:8000/admin 經過Django自動的後臺進行問題添加

 

11. 編寫視圖控制層

視圖起着承前啓後的做用，前是指前端頁面，後是指後臺數據庫。將數據庫表中的內容查詢出來顯示到頁面上。

編寫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.
# 首頁展現全部問題
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)


# 查看全部問題
def detail(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/detail.html', {'question': question})


# 查看投票結果
def results(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/results.html', {'question': question})


# 選擇投票
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,)))

　　

12. 配置視圖展現層與邏輯控制層url映射

url是一個請求配置文件，頁面中的請求轉交給由哪一個函數處理，由該文件決定。

首先配置polls/urls.py(該文件須要建立)

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，編輯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)),
]

　　

13. 建立視圖模板

模板就是前端頁面，用來將數據顯示到web頁面上。

首先建立polls/templates/polls/目錄，分別在該目錄下建立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>

　　

14. 啓動web容器，訪問：http://127.0.0.1:8000/polls/