I am creating an API using Django Restframework which needs data from multiple models. I got many answers for my requirement but it isn't working.

I have my models as follows

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

Here's my view function

@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

I am getting the json as following

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

What changes should I do to Serializers.py so that my json output is as following

[
    {
        "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"
            }
        ],
        
    }
]

The depth = 1 attribute in meta class should have got the work done according to other stackoverflow questions, but it isn't working.

CodePudding user response：

You use a subserializer, so:

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

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

In the view you can boost efficiency by prefetching the task_extendeds:

@api_view(['GET'])
def taskList(request):
    tasks = Task.objects.prefetch_related('task_extendeds')
    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.

CodePudding user response：

Write a Task_extendedSerializer first then use it in 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')