如何序列化多个模型对象？

Question

我正在使用需要来自多个模型的数据的 Django Restframework 创建 API。我的要求得到了很多答案，但没有用。

我的模型如下

class Task(models.Model):
    title = models.CharField(max_length=200)
    completed = models.BooleanField(default=False, blank=True, null=True)

    def __str__(self):
        return self.title

class Task_extended(models.Model):
    task_id = models.ForeignKey(Task, on_delete = models.CASCADE,related_name='task_extendeds')
    field_3 = models.CharField(max_length=200)
    field_5 = models.CharField(max_length=200)
    field_4 = models.BooleanField(default=False, blank=True, null=True)

    def __str__(self):
        return self.field_3

这是我的视图函数

@api_view(['GET','POST'])
def taskList(request):
    tasks = Task.objects.all()
    serializer = TaskSerializer(tasks, many =True)
    return Response(serializer.data)

Serializer.py

class TaskSerializer(serializers.ModelSerializer):
    task_extendeds = serializers.PrimaryKeyRelatedField(many=True, read_only=True)
    class Meta:
        model = Task
        fields = "__all__"
        depth = 1

我得到 json 如下

[
    {
        "id": 2,
        "task_extendeds": [
            1,
            2,
            3
        ],
        "title": "Start Rest Framework",
        "completed": false
    }
]

我应该对 Serializers.py 做哪些更改，以便我的 json 输出如下

[
    {
        "id": 2,
        "title": "Start Rest Framework",
        "completed": false,
        "task_extendeds": [
            {
                "field_3": "Field 3 Data",
                "field_4": "Field 4 Data",
                "field_5": "Field 5 Data"
            },
            {
                "field_3": "Field 3 Data",
                "field_4": "Field 4 Data",
                "field_5": "Field 5 Data"
            },
            {
                "field_3": "Field 3 Data",
                "field_4": "Field 4 Data",
                "field_5": "Field 5 Data"
            }
        ],
        
    }
]

根据其他 Whosebug 问题，meta class 中的 depth = 1 属性本应完成工作，但它不起作用。

Answer 1

您使用了子序列化程序，因此：

class <strong>Task_extendedSerializer</strong>(serializers.ModelSerializer):
    class Meta:
        model = Task_extended
        fields = ['field_3', 'field_4', 'field_5']

class TaskSerializer(serializers.ModelSerializer):
    task_extendeds = serializers.<strong>Task_extendedSerializer(</strong>many=True<strong>)</strong>
    
    class Meta:
        model = Task
        fields = '__all__'

在视图中，您可以通过预取 task_extendeds:

来提高效率

@api_view(['GET'])
def taskList(request):
    tasks = Task.objects<strong>.prefetch_related('task_extendeds')</strong>
    serializer = TaskSerializer(tasks, many=True)
    return Response(serializer.data)

Note: Models in Django are written in PascalCase, not snake_case, so you might want to rename the model from ~~Task_extended~~ to TaskExtended.

Answer 2

先写一个Task_extendedSerializer然后用在TaskSerializer

class Task_extendedSerializer(serializers.ModelSerializer):
    class Meta:
        model = Task_extended
        fields = ('field_3', 'field_4', 'field_5')


class TaskSerializer(serializers.ModelSerializer):
    task_extendeds = Task_extendedSerializer()
    class Meta:
        model = Task
        fields = ('id', 'title', 'completed', 'task_extendeds')

如何序列化多个模型对象？

How to serialize multiple model object?

django

foreign-keys

django-models

django-serializer

django-rest-framework