Django Rest Framework中的分组和嵌套结果

Question

我在 API 中工作，我想按 id DESC 排序，但我也想按 client_id 分组，所以我可以将来自同一客户的所有问题都排序，嵌套结果：

这是我的代码：

models.py

class QuestionsModel(models.Model):
    id = models.IntegerField()
    publication_id = models.IntegerField(blank=True, null=True)
    publication_title = models.CharField(max_length=255)
    publication_link = models.CharField(max_length=255)
    question = models.CharField(max_length=255)
    member_id = models.IntegerField()
    client_id = models.IntegerField()

   class Meta:
        managed = False
        db_table = 'questions'

序列化器.py

class QuestionsSerializer(serializers.ModelSerializer):
    class Meta:
        model = QuestionsModel
        fields = '__all__'

views.py

class QuestionsAPIView(generics.ListAPIView):
    def get_queryset(self):
        queryset = ''
        member_id = self.request.query_params.get('member_id')
        
        if member_id is not None and member_id.isnumeric():
            queryset = QuestionsModel.objects.filter(member_id=member_id).order_by('-id')
        return queryset

结果：

    {
    "id": 848484,
    "publication_id": 4444,
    "publication_title": "Title publication",
    "publication_link": "Link",
    "question": "This is a test question",
    "member_id": 123456,
    "client_id": 500
    }

我想要什么：按 client_id 分组问题，所以希望输出 JSON 可能是：

{
"client_id": 500,
"question" : [
    "id": 848484,
    "publication_id": 4444,
    "publication_title": "Title publication",
    "publication_link": "Link",
    "question": "This is a test question",
    "member_id": 123456,
    "client_id": 500
 ],
[
    "id": 848485,
    "publication_id": 4445,
    "publication_title": "Title publication",
    "publication_link": "Link",
    "question": "This is a test question",
    "member_id": 123456,
    "client_id": 500
]
}

注意：我使用 SQL Server 作为数据库引擎。

Answer 1

如果客户和问题之间存在“一对多”关系，我建议创建一个客户模型并在问题与其客户之间建立外键关系。然后，您可以更轻松地利用 DRF 的模型序列化程序和嵌套关系。

https://www.django-rest-framework.org/api-guide/relations/#nested-relationships

这是我认为您正在努力实现的简化版本：

models.py

class Client(models.Model):
    id = models.IntegerField(primary_key=True)

class Question(models.Model):
    id = models.IntegerField(primary_key=True)
    question = models.CharField(max_length=255)
    client_id = models.ForeignKey(to=Client,on_delete=models.CASCADE,related_name='questions')

序列化器.py

class QuestionSerializer(serializers.ModelSerializer):
    class Meta:
        model = Question
        fields = ['id','question']


class ClientSerializer(serializers.ModelSerializer):
    questions = QuestionSerializer(many=True, read_only=True)

    class Meta:
        model = Client
        fields = ['id','questions']

views.py

class ClientList(generics.ListAPIView):
    queryset = Client.objects.all()
    serializer_class = ClientSerializer

如果我将此视图连接到一个 URL 并对其调用 GET，则生成的数据结构是：

[
    {
        "id": 1,
        "questions": [
            {
                "id": 1,
                "question": "questions 1"
            },
            {
                "id": 2,
                "question": "questions2"
            },
            {
                "id": 3,
                "question": "questions3"
            }
        ]
    }
]

我不确定你打算让谁使用你的 API，但作为一个经常使用 REST 的人，这个数据结构对我来说比你建议的更直观。这是一个客户对象列表（尽管在此示例中只包含一个），下面有一个嵌套的问题对象列表。根据需要扩展您的模型并优化您的查询集！