Question

也许因为所有树木都看不到森林，但我有一个非常奇怪的问题。

views.py：

from django.shortcuts import render
from models import Question, QuestionAnswerAlloc, Section

def home(request):
    sections = Section.objects.all()
    for s in sections:
        questions = Question.objects.filter(section=s)
        for q in questions:
            answersalloc = QuestionAnswerAlloc.objects.filter(question=q)
            q.answers.append(answersalloc)
        s.questions.append(questions)

    return render(request, "questionaire/index.html", {'sections': sections})

models.py：

from django.db import models

from portal.models import Customer


class Section(models.Model):
    title = models.CharField(max_length=150)
    weight = models.FloatField()
    maxscore = models.FloatField()

    questions = []

    def __unicode__(self):
        return "%s" % (self.title)


class Question(models.Model):
    title = models.TextField()
    section = models.ForeignKey(Section)
    weight = models.FloatField()

    answers = []

    def __unicode__(self):
        return self.title


class Answer(models.Model):
    title = models.CharField(max_length=150)
    points = models.IntegerField(default=0, help_text="This has to be a value between 0 and 5")
    is_weighted = models.BooleanField(default=True, help_text="If this answer does not apply (N/a) it is not weighted!")

    def __unicode__(self):
        return self.title


class QuestionAnswerAlloc(models.Model):
    question = models.ForeignKey(Question)
    answer = models.ForeignKey(Answer)

    def __unicode__(self):
        return "Possible Answer"


class Report(models.Model):
    STATUS_STARTED = "started"
    STATUS_FIN = "finished"
    STATUS_INPROG = "inprogress"
    STATUS_ABORT = "aborted"

    date = models.DateField(auto_now_add=True, blank=True)
    title = models.CharField(max_length=150)
    started_time = models.DateTimeField()
    end_time = models.DateTimeField()
    status = models.CharField(max_length=150, default=STATUS_STARTED)
    guid = models.CharField(max_length=150, unique=True)

    def __unicode__(self):
        return self.title


class ReportAnswer(models.Model):
    title = models.CharField(max_length=150)

    orignal_answer = models.ForeignKey(Answer)
    question = models.ForeignKey(Question)
    section = models.ForeignKey(Section)
    report = models.ForeignKey(Report)

    points = models.FloatField()
    weight = models.FloatField()
    is_weighted = models.BooleanField(default=True)

    customer = models.ForeignKey(Customer, blank=True, null=True)

    def __unicode__(self):
        return self.title

我的模板：

{% for s in sections %}
            <div class="row">
                <div class="col-sm-12">
                    <div class="FormStepInfo">
                        <p class="QuestionaireSectionTitle">{{s.title}}</p>
                        <p class="QuestionaireSectionDesc"></p>
                    </div>
                </div>
            </div>

                {% for q in s.questions %}
                <div class="row">
                    <hr/>
                    <div class="col-sm-2 quest-num">{{forloop.counter }}</div>
                    <div class="col-sm-10 quest-title">
                        <label>
                            {{q.title}}
                        </label>
                        <br/>

                        <div class="CheckboxQuestion">
                            {% for a in q.answers %}
                            <label for=""><input type="radio" name="Q3" value="{{a.points}}" id="q3a1">{{a.title}}</label>
                            {% endfor %}
                        </div>
                    </div>
                </div>
                {% endfor %}
            {% endfor %}

不幸的是，问题标题没有显示，也没有显示答案。如果我打印到sys.stderr，我可以看到有部分问题。我错过了什么吗？我已经重新启动了我的＆＃34; webserver＆＃34;，因为我正在使用＆＃34; python manage.py runserver＆＃34;大约10次并删除了我的缓存。

Answer 1

你对Python中的类定义有一个相当大的误解。通常，当您在类级别定义属性时，它将由该类的所有成员共享。 Django字段做了一些特殊的魔术，以确保值是每个实例而不是每个类，但您的questions和answers列表不会这样做。因此，即使您可以让代码工作，所有答案都会与所有问题相关联。

幸运的是，没有必要这样做。 Django为您提供了反向访问器，可以提供您所需的内容。所以视图可以简化为：

def home(request):
    sections = Section.objects.all()
    return render(request, "questionaire/index.html", {'sections': sections})

并且视图变为：

{% for s in sections %}
   ...
   {% for q in s.question_set.all %}
       ...
       {% for a in q.questionansweralloc_set.all %}

       ...etc

Django子模型不会出现在模板中

1 个答案: