Django创建投票应用

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, on_delete=models.CASCADE)

    choice_text = models.CharField(max_length=200)

    votes = models.IntegerField(default=0)

激活模型

mysite\\setting.py

python 复制代码

INSTALLED_APPS = [

    "polls.apps.PollsConfig",

    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",

]

为模型的改变生成迁移文件

bash 复制代码

python manage.py makemigrations polls

应用数据库迁移

python 复制代码

python manage.py migrate

创建管理员账号

python 复制代码

python manage.py createsuperuser

管理投票应用

mysite\\polls\\admin.py

python 复制代码

from django.contrib import admin
from .models import Question,Choice

# class ChoiceInline(admin.StackedInline):

#     model = Choice

#     extra = 3

# 通过 TabularInline （替代 StackedInline ）  单行显示关联

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]

  
  

admin.site.register(Question, QuestionAdmin)

添加视图

mysite\\polls\\views.py

python 复制代码

from django.shortcuts import render, get_object_or_404,HttpResponseRedirect
from django.http import HttpResponse
from django.urls import reverse
from .models import Question,Choice

def index(request):
    latest_question_list = Question.objects.order_by("-pub_date")[:5]
    template = "polls/index.html"
    context = {
        "latest_question_list": latest_question_list,
    }
    return render(request,template,context)

def detail(request,question_id):
    question = get_object_or_404(Question,pk=question_id)
    template = "polls/detail.html"
    context = {
        "question":question,
    }

    return render(request,template,context)

def results(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    template = "polls/results.html"
    context = {
        "question": question,
    }

    return render(request,template,context)

def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST["choice"])
    except (KeyError, Choice.DoesNotExist):
        template = "polls/detail.html"
        context = {
                "question": question,
                "error_message": "You didn't select a choice.",
        }
        return render(request,template,context)
    else:

        selected_choice.votes += 1
        selected_choice.save()

        return HttpResponseRedirect(reverse("polls:results", args=(question.id,)))

添加路径

mysite\\polls\\urls.py

python 复制代码

from django.urls import path
from . import views

app_name = "polls"
urlpatterns = [
    path("", views.index, name="index"),
    path("<int:question_id>/", views.detail, name="detail"),
    path("<int:question_id>/results/", views.results, name="results"),
    path("<int:question_id>/vote/", views.vote, name="vote"),
]

mysite\\urls.py

python 复制代码

from django.contrib import admin
from django.urls import path,include

urlpatterns = [
    path("polls/",include("polls.urls")),
    path("admin/", admin.site.urls),
]

创建模版

mysite\\polls\\templates\\polls\\index.html

html 复制代码

<!DOCTYPE html>

<html lang="zh">

<head>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <title>Document</title>

</head>

  

<body>

    {% 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 %}

</body>

</html>

mysite\\polls\\templates\\polls\\detail.html

html 复制代码

<!DOCTYPE html>

<html lang="zh">

<head>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <title>Document</title>

</head>


<body>

    <form action="{% url 'polls:vote' question.id %}" method="post">

        {% csrf_token %}

        <fieldset>

            <legend>

                <h1>{{ question.question_text }}</h1>

            </legend>

            {% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %}

            {% 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 %}

        </fieldset>

        <input type="submit" value="Vote">

    </form>

  

</body>

</html>

mysite\\polls\\templates\\polls\\results.html

html 复制代码

<!DOCTYPE html>

<html lang="zh">

<head>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <title>Document</title>

</head>

<body>

    <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>

</body>

</html>

启动开发服务器

python manage.py runserver

管理地址

http://127.0.0.1:8000/admin/
应用地址

http://127.0.0.1:8000/polls/