django如何获得对许多领域的计数 [英] django how to get count for manytomany field

问题描述

我有问题模型：

class Question(models.Model):
    user = models.ForeignKey(User)
    title = models.CharField(max_length=120)
    description = models.TextField()
    answers = models.ManyToManyField('Answer',related_name='answer_name', blank=True)
    post_date = models.DateTimeField(auto_now=True)

def __unicode__(self):
    return self.title

我有答案模型：

class Answer(models.Model):
    user = models.ForeignKey(User)
    question = models.ForeignKey(Question)
    ans_body = models.TextField()
    post_date = models.DateTimeField(auto_now=True)

def __unicode__(self):
    return self.ans_body

问题创建和答案提交工作正常。我无法正确显示特定问题的答案。但是，当我尝试获取特定问题的答案数量时，它没有显示。它显示为0。

Question creation and answer submission are working perfectly. I cant correctly show answer for particular question. But when I try to get the count of answer for particular question its not showing. It displays 0 count.

在我看来，我的答案列表是：

In my view I am getting the list of the answer by:

context["question_list"] = Question.objects.all()

在我的模板中

{% for question in question_list %}
   {{ question.title }}
    Ans:{{question.answers.count}}
{% endfor %}

当我这样做时，如果有答案，我将得到计数0。

When I do this I get the count 0 if there are answers. How can I get the count of the answers for particular questions.

推荐答案

这可行：

{{question.answer_set.count}}

快乐..

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