Question

我有三个模型，一个主题可以有零个或多个问题，一个问题可以有零个或多个答案。只有一个答案是正确的。

他们是多对一的关系。

class Topic(models.Model):

class Question(models.Model):
    topic = models.ForeignKey(Topic)

class Answer(models.Model):
    question = models.ForeignKey(Question) 
    isright = models.BooleanField(verbose_name='Right')

现在我尝试根据主题循环问题，如何使用模板实现它？

<topic>

  <question>
    <answer>
    <answer>
    <answer>
    <answer>

  <question>
    <answer>
    <answer>
    <answer>
    <answer>

如何为问题添加分页器？

paginator = Paginator(topic.question_set.all(), 25)

Answer 1

如果我理解得很好，你想要循环“主题”排序的答案：

answers = Answer.objects.order_by('question__topic', 'question')

或：

for topic in Topic.objects.all():
    for question in topic.question_set.all():
        for answer in question.answer_set.all():
            ...do something...

在模板中，您可以执行相同操作，将变量topics作为Topic.objects.all（）：

{% for topic in topics %}
    {% for question in topic.question_set.all %}
        {% for answer in question.answer_set.all %}
            ...do something...
        {% endfor %}
    {% endfor %}
{% endfor %}

Answer 2

使用* _set.all（）变量：

 t = Topic.objects.get(id=X)
 questions = t.question_set.all()

 for q in questions:
     answers = q.answer_set.all()

     for a in answers:
          print a

Answer 3

topic_instance.question_set.all()

请参阅docs

Django查询多对一关系

3 个答案: