从 1:M 相关 Models DRF 中查询对象答案

【问题标题】：Querying objects from 1:M related Models DRF从 1:M 相关 Models DRF 中查询对象
【发布时间】：2019-06-18 01:14:36
【问题描述】：

设计了一个具有多级 1:M 关系的 Django 模型，能够在 DRF 中获取写入序列化器的 json 响应。执行 CRUD 操作看起来很容易，但只针对该表，我期待响应类似于下面的响应，然后遇到了一个名为 Nested Serializers 的术语，因为我不太了解这一点，有人可以建议我为以下型号买一个吗

{
  "Blocks": [
    {
      "id": 1,
      "name": "A",
      "Floor": [
        {
          "id": 1,
          "name": 0,
          "count":2,
          "books": [
            {
              "id": 1,
              "name": "White Tiger"
            },
            {
              "id": 1,
              "name": "The Alchemist"
            }
          ]
        },
        {
          "id": 2,
          "name": 1,
          "count": 2,
          "books": [
            {
              "id": 1,
              "name": "Facebook"
            },
            {
              "id": 1,
              "name": "The Master Blaster"
            }
          ]
        }
      ]
    },
    {
      "id": "2",
      "name": "B",
      "Floor": [
        {
          "id": 1,
          "name": 0,
          "count":2,
          "books": [
            {
              "id": 1,
              "name": "Know Your self"
            },
            {
              "id": 1,
              "name": "The Naga"
            }
          ]
        },
        {
          "id": 2,
          "name": 1,
          "count":2,
          "books": [
            {
              "id": 1,
              "name": "The Data Analyics"
            },
            {
              "id": 1,
              "name": "Become Master of R"
            }
          ]
        }
      ]
    }
  ]
}

每当添加/删除一本书时，它都应该反映在楼层的count属性中

【问题讨论】：

标签： django django-models django-rest-framework

【解决方案1】：

根据the documentation，对于只读，这样的东西应该可以工作：

class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model = Book

class FloorSerializer(serializers.ModelSerializer):
    book = BookSerializer(many=True, read_only=True)

    class Meta:
        model = Floor

class BlockSerializer(serializers.ModelSerializer):
    Floor = FloorSerializer(many=True, read_only=True)

    class Meta:
        model = Block

For writing/updating, 将 create 和/或 update 方法写入 BlockSerializer。

class BlockSerializer(serializers.ModelSerializer):
    Floor = FloorSerializer(many=True)

    class Meta:
        model = Block

    def create(self, validated_data):
        floors_data = validated_data.pop('Floors')
        block = Blocks.objects.create(**validated_data)
        for floor_data in floors_data:
            books_data = floor_data.pop('books')
            floor = Floor.objects.create(block=block, **floor_data)
            for book_data in books_data:
                Book.objects.create(floor=floor, **book_data)

希望对你有帮助

【讨论】：