python - Django 评级错误 : "rating value must be a Rating instance, not ' 100"?

Question

我尝试通过 Django 评级应用程序评级来排序一组模型对象。我在我看来构建了一个 order_by 函数，该函数工作正常，但当我进入评级字段时，我收到此错误:“评级值必须是评级实例，而不是'100”。任何想法有什么问题/或者错误意味着什么？

谢谢!

模板:

<a href="/mylist/?order_by=rating">Order by Rating</a>

查看:

def Mylist(request):    
    order_by = request.GET.get('order_by', 'created_date')  
    mylist = Mymodel.objects.filter(user=request.user).order_by(order_by)

    if order_by == "rating":
        qs = Mymodel.objects.filter(user=request.user).extra(select={
        'rating': '((100/%s*rating_score/(rating_votes+%s))+100)/2' % (Mymodel.rating.range, Mymodel.rating.weight)
        })
        mylist = qs.order_by('-rating')

    context = {'mylist ': mylist }
    return render_to_response('mylist.html', context, context_instance=RequestContext(request))

型号:

class Mymodel(models.Model):
   user = models.ForeignKey(User)
   created_date = models.DateField(auto_now_add=True)
   type = models.CharField(max_length=50)
   description = models.CharField(max_length=140, blank=True)
   rating = RatingField(range=5)

Answer 1

尝试重命名额外属性“评级”

queryset = queryset.extra(select={
    'myrating': '((100/%s*rating_score/(rating_votes+%s))+100)/2' % (Mymodel.rating.range, Mymodel.rating.weight)
})
queryset = queryset.order_by('-myrating')