Get common values in django queryset-CodePudding

I am building a Quiz Application. I have a simple queryset, where I want to filter all the right answers given by the user. So far so good. After that, I would like to obtain the results, divided per subject, si I am trying to figure a way to filter even more. I post some code for better understanding:

models.py

class QuestionDraft(models.Model):
    quiz_profile = models.ForeignKey(QuizProfile,
                                 on_delete=models.CASCADE,
                                 blank=True,
                                 null=True)
    question = models.ForeignKey(Question,
                             on_delete=models.CASCADE,
                             blank=True,
                             null=True)
    text = models.TextField()
    is_answered = models.BooleanField(blank=True, null=True)
    is_correct = models.BooleanField(blank=True, null=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

class Question(models.Model):
    id = models.CharField(max_length=7,
                      default=generate_question_id,
                      unique=True,
                      primary_key=True,
                      editable=False)
    question_subject = models.ForeignKey(
    QuestionSubject, on_delete=models.CASCADE)
    text = models.TextField()
    mark = models.IntegerField(default=1)
    is_published = models.BooleanField(default=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

class QuestionSubject(models.Model):
    quiz_course = models.ForeignKey(QuizTheoryCourse, on_delete=models.CASCADE)
    name = models.CharField(max_length=200)
    exam_questions_num = models.IntegerField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

In my views I am trying, initially to filter the correct answers (which I am getting right) and after that to group the right answers per subject. Let's say, I have 10 different subjects

views.py

def test_report(request, pk):
    quiz_profile = QuizProfile.objects.get(id=pk)
    question_drafts = QuestionDraft.objects.filter(quiz_profile=quiz_profile)
    total_questions = question_drafts.count()
    right_answers = quiz_profile.right_answer
    quiz_percentage = ((right_answers * 100) / total_questions)
    wrong_answers = total_questions - quiz_profile.right_answer

    right_ans = QuestionDraft.objects.filter(
    quiz_profile=quiz_profile, is_correct=True)
    subjects = [
    question.question.question_subject for question in right_ans]
    right_ans_list = []
    for s in subjects:
        print(right_ans.filter(question__question_subject=s).count())

context = {
    'quiz_profile': quiz_profile,
    'total_questions': total_questions,
    'quiz_percentage': quiz_percentage,
    'wrong_answers': wrong_answers,
    'right_answers': right_answers,
    'subjects': subjects,
}
return render(request, 'quiz/test_report.html', context)

I tried many different ways but I couldn't find a proper way how to loop through or filter even more.

CodePudding user response：

Can you try this? this should give you subjects for Specific Quiz and question count which have been answered.

questions = QuestionDraft.objects.filter(quiz_profile_id=quiz_profile, is_answered=True).annotate(que_count=Count('question__question_subject_id')).values("question__question_subject__name","que_count")