Is it possible to have two ManyToMany relationships to the same model on the same admin page?

Question

I modelling a quiz and the associated questions as follows:

# models
class Question(models.Model):
    title = models.TextField()
    category = models.TextField()


class Quiz(models.Model):
    questions = models.ManyToManyField(Question, through='OrderedQuestion')


class OrderedQuestion(models.Model):
    # A through table to allow ordering of questions
    question = models.ForeignKey(Question, ...)
    quiz = models.ForeignKey(Quiz, ...)
    order = models.PositiveIntegerField(default=0)

I have two types of questions that are handled by proxy models:

# proxy models to handle specific question categories
class BoatQuestion(Question):
     objects = BoatQuestionManager()  # handles setting category

     class Meta:
         proxy = True

and a similar one for CarQuestion .

I want to be able to edit BoatQuestions and CarQuestions independently from each other but on the same admin page. The admin setup is:

class BoatQuestionInline(admin.TabularInline):
    model = BoatQuestion.quiz.through


class CarQuestionInline(admin.TabularInline):
    model = CarQuestion.quiz.through


class QuizAdmin(admin.ModelAdmin):
    model = Quiz
    inlines = (BoatQuestionInline, CarQuestionInline)

but whenever I change the questions in the boat question section, the questions in the car section update to match it and vice versa.

Is there any way to show these on the same admin page but change them independently?

Answer 1

The problem lies in your inlines. You use the same model for both, which is fine. But as you want to show only certain Question s, you have to adjust the QuerySet for each inline and add an appropriate .filter() . (I am guessing here, how you distinguish the category of the questions.)

class BoatQuestionInline(admin.TabularInline):
    model = BoatQuestion.quiz.through

    def get_queryset(self, *args, **kwargs):
        return OrderedQuestion.objects.filter(question__category='boat')


class CarQuestionInline(admin.TabularInline):
    model = CarQuestion.quiz.through

    def get_queryset(self, *args, **kwargs):
        return OrderedQuestion.objects.filter(question__category='car')