如何基于Django中的两个字段对queryset进行排序？

Question

This is my serilizer class:

class RankNewsChannelSerializers(serializers.ModelSerializer):
    class Meta:
        model = News_Channel
        fields = ('id', 'name','total_star', 'total_user')

This is my view:

class NewsChannelRankApi(ListAPIView):
    queryset = News_Channel.objects.order_by('-total_star').all()
    serializer_class = RankNewsChannelSerializers

The response I'm getting is sorted, based on total_stars , as shown below:

[
    {
        "id": 9,
        "name": "The Hindu",
        "total_star": 36,
        "total_user": 5
    },
    {
        "id": 1,
        "name": "NDTV",
        "total_star": 36,
        "total_user": 5
    },
    {
        "id": 10,
        "name": "Firstpost",
        "total_star": 35,
        "total_user": 6
    },
    {
        "id": 14,
        "name": "DD News",
        "total_star": 25,
        "total_user": 4
    }
]

But I need the response to be sorted by total_star/total_user . Like this is my invalid method, but it will give you a rough idea of what I want to achieve.

class NewsChannelRankApi(ListAPIView):
    queryset = News_Channel.objects.order_by('-total_star/total_user').all()
    serializer_class = RankNewsChannelSerializers

Please help me if there is anyway to do so?

Answer 1

You can add a field with the value you want and then order by it. Also, you don't need the .all()

    queryset = News_Channel.objects \
         .annotate(stars_per_user=F('total_star')/F('total_user')) \
         .order_by('-stars_per_user')