[django实践]投票app

code: https://github.com/lannyMa/toupiao

polls app介绍

这个例子来源于django官网,恰好2.x版本有中文版. https://docs.djangoproject.com/zh-hans/2.0/intro/tutorial01/

功能介绍

• 首页
  

• 投票
  

• 投票结果页
  

从首页点选项,进入投票(detail)页, 选择-vote(result),跳转到投票页重新投票

代码里值得学习的

1.取出关联表中的数据

detail.html

<h1>{{ question.question_text }}</h1>
<ul>
{% for choice in question.choice_set.all %}
    <li>{{ choice.choice_text }}</li>
{% endfor %}
</ul>

2: url的redirect和reverse

from django.http import HttpResponseRedirect
from django.shortcuts import render, get_object_or_404
from app01.models import Question, Choice
from django.urls import reverse

path('specifics/<int:question_id>/', views.detail, name='detail'),


<li><a href="{% url 'detail' question.id %}">{{ question.question_text }}</a></li>

return HttpResponseRedirect(reverse('app02:results', args=(question.id,)))

取出所有和取出某一个

https://docs.djangoproject.com/zh-hans/2.0/intro/tutorial04/

关于时间

class Question(models.Model):
    question_text = models.CharField(max_length=50)
    pub_date = models.DateTimeField(timezone.now())

    def was_published_recently(self):
        return self.pub_date >= timezone.now() - datetime.timedelta(days=1)

    def __str__(self):
        return self.question_text


class Choice(models.Model):
    question_text = models.ForeignKey(Question, on_delete=models.CASCADE)
    choice_text = models.CharField(max_length=50)
    votes = models.IntegerField(default=0)

    def __str__(self):
        return self.choice_text

>>> from django.utils import timezone
>>> q = Question(question_text="What's new?", pub_date=timezone.now())

关于get_object_or_404

https://docs.djangoproject.com/zh-hans/2.0/intro/tutorial03/

detail

from django.http import Http404
from django.shortcuts import render

from .models import Question
# ...
def detail(request, question_id):
    try:
        question = Question.objects.get(pk=question_id)
    except Question.DoesNotExist:
        raise Http404("Question does not exist")
    return render(request, 'polls/detail.html', {'question': question})

from django.shortcuts import get_object_or_404, render

from .models import Question
# ...
def detail(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/detail.html', {'question': question})