Django order_by 将查询集随机化两次？

Question

I am trying to randomize a query set for a program i'm working on.

This is what's is in my views.py

full_quiz = Quiz.objects.get(name=quiz_name).questions.all()
form = TheForm(full_quiz)
if request.method == "POST":
    form = QuestionForm(request.GET, full_quiz)

This is what is in my forms.py

class QuestionForm(forms.Form):
def __init__(self, questions, *args, **kwargs):
    super(QuestionForm, self).__init__(*args, **kwargs)
    for i in range(len(questions)): 
        if questions[i].answer.count() < 2:
            self.fields["field_name %d" % i] = forms.CharField(label=questions[i], required=False)

From my testing, it appears like the query set is getting randomized with the second form variable. Any fix for this?

Thanks

Answer 1

You can get a random order queryset as described here :

full_quiz = Quiz.objects.get(name=quiz_name).questions.order_by('?')

You have not posted the code of your forms but I expect QuestionForm is a ModelFormSet. You can change the queryset of a ModelFormSet by setting the queryset arg (see docs ):

form = QuestionForm(queryset=fullquiz)

Suppose you have a model structure like this

class Quiz(models.Model):

    name = models.CharField('Quizname', max_length=200)
    questions = models.ManyToManyField('Question')

class Answer(models.Model):

    reply = models.CharField('Answer', max_length=100)

class Question(models.Model):

    the_question = models.CharField('Question', max_length=100)
    answers = models.ManyToManyField('Answer', related_name='answers')
    correct_answer = models.ForeignKey('Answer', on_delete=models.CASCADE)

    def is_correct(self, given_answer):
        return given_answer == self.correct_answer

you could create a form structure with a ModelForm and a ModelFormSet :

class QuestionForm(forms.ModelForm):
    myanswers = forms.ModelChoiceField(queryset=Answer.objects.all(), widget=forms.RadioSelect, required=False)
    class Meta:
        model = Question
        fields = ('the_question', 'myanswers')

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['myanswers'].queryset = self.instance.answers.all()


QuestionFormSet = modelformset_factory(Question, form=QuestionForm, extra=0)

And use it in a view:

def myview(request, quiz_name):

  if request.method == 'POST':
      formset = QuestionForm(request.POST)
      if form.is_valid():
          allanswers = [f['id'].is_correct(f['myanswers']) for f in formset.cleaned_data]
          print('Number of correct answers:', sum(allanswers))

  fullquiz = Quiz.objects.get(name=quiz_name).questions.order_by('?')
  formset = QuestionForm(queryset=fullquiz)
  return render(request, 'yourtemplate.html', {'formset': formset })