Django外键模型计数

Django外键模型计数

您可以 使用

.annotate()

获得的计数

answers

与各关联

question

。

from django.db.models import Countquestions = Question.objects.annotate(number_of_answers=Count('answer')) # annotate the queryset

这样，每个

question

对象将具有一个额外的属性

number_of_answers

，该属性的值与每个对象

answers

相关联

question

。

questions[0].number_of_answers # access the number of answers associated with a question using 'number_of_answers' attribute

最终代码：

from django.db.models import Countdef all_questions(request):    questions = Question.objects.annotate(number_of_answers=Count('answer'))    return render(request, 'all_questions.html', { 'questions':questions})

在模板中，您可以执行以下 *** 作：

{% for question in questions %}    {{question.number_of_answers}} # displays the number of answers associated with this question