在Django中基于ForeignKeys的查询集

Question

While learning Django I am creating an example app in which I have two types of users; students and educators. Educators can create Study sections and students can choose which they would like to participate in (just a BooleanField yes or no). I would like to create a "view participants" page for each study so that the educators can see which students are participating in each section. To do this for each study section I need to query all of the student users who marked "yes" to participate in that study section. I am a bit stuck on how to use Django's QuerySet methods to do this.

Here is my models.py

class User(AbstractUser):
    is_student = models.BooleanField(default=False)
    is_educator = models.BooleanField(default=False)


class Interest(models.Model):
...


class Study(models.Model):
    owner = models.ForeignKey(User, on_delete=models.CASCADE, related_name='studies')
    name = models.CharField(max_length=255)
    interest = models.ForeignKey(Interest, on_delete=models.CASCADE, related_name='studies')

    def __str__(self):
        return self.name


class Detail(models.Model):
...


class Student(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, primary_key=True)
    interests = models.ManyToManyField(Interest, related_name='interested_students')

    def get_details(self, study):
        details = study.details.all().order_by('start_date')
        return details

    def __str__(self):
        return self.user.username


class StudentAnswer(models.Model):
    student = models.ForeignKey(Student, on_delete=models.CASCADE, related_name='study_answers')
    study = models.ForeignKey(Study, on_delete=models.CASCADE, related_name='study_participate', null=True)
    participate = models.BooleanField('Correct answer', default=False)

I would like to write a views.py function like this:

@method_decorator([login_required, educator_required],     name='dispatch')
class StudyResultsView(DetailView):
    model = Study
    context_object_name = 'study'
    template_name = 'classroom/educators/study_results.html'

    def get_context_data(self, **kwargs):
        study = self.get_object()
        participants = study.????
        total_participants = participants.count()
        extra_context = {
            'participants': participants,
            'total_participants': total_participants,
        }
        kwargs.update(extra_context)
        return super().get_context_data(**kwargs)

    def get_queryset(self):
        return self.request.user.studies.all()

But I cannot figure out what the correct query should be at participants = study.???? in order to select all of the users who marked participate=True for that study.

Answer 1

participants = study.objects.filter(study_participate__participate = True)

这肯定会工作。