Django內聯formset通過另一個模型過濾多種關系

Question

我有兩個模型SchoolClass和Student，它們通過Enrollment模型有多對多的關系。

class Student(models.Model):
    name = models.CharField(max_length=100)
    code = models.CharField(max_length=10)

class SchoolClass(models.Model):
    code = models.CharField(max_length=100)
    cycle = models.ForeignKey(Cycle)
    students = models.ManyToManyField(Student,through='Enrolment')

class Enrolment(models.Model):
    student = models.ForeignKey(Student)
    school_class = models.ForeignKey(SchoolClass)

SchoolClass模型有一個字段循環（這是課程運行的年份+學期。當我在管理員中查看學生時，我希望看到學生僅在給定周期內注冊的課程（例如當前周期）

我以前在Enrollment模型中有了循環字段，以下工作很好：

class StudentEnrolmentsInlineFormSet(BaseInlineFormSet):
    def get_queryset(self):
        if not hasattr(self, '_queryset'):
            qs = super(StudentInlineFormSet, self).get_queryset().filter(cycle=Current)
            self._queryset = qs
        return self._queryset

class StudentEnrolmentsInline(admin.TabularInline):
    model = Enrolment
    formset = StudentEnrolmentsInlineFormSet

class StudentAdmin(admin.ModelAdmin):
    form = StudentForm
    inlines = (StudentEnrolmentsInline,)

但是，我已經在SchoolClass模型中移動了循環，現在無法確定如何將過濾器應用到下一個模型。

Answer 1

除非我忽略了某些內容，否則可以使用StudentEnrolmentsInline上的queryset方法執行此操作：

def queryset(self, request):
    current = Cycle.objects.latest() # or whatever to get the current cycle
    qs = super(StudentEnrolmentsInline, self).queryset(request)
    return qs.filter(school_class__cycle=current)