从模型中返回嵌套的 JSON 与 Django 中的关系

Question

models.py（简化版）

class Author(models.Model):

    name = models.CharField(max_length=255)
    
    def __str__(self):
        return self.name

    def get_books(self):
        return Book.objects.filter(author=self.pk)


class Book(models.Model):

    name = models.CharField(max_length=255)
    pages = models.IntegerField()
    author = models.ForeignKey(Author, on_delete=models.CASCADE)

    def __str__(self):
        return f'{self.name} from {self.author}'


class Paragraph(models.Model):

    name = models.CharField(max_length=255)
    book = models.ForeignKey(Book, on_delete=models.CASCADE)


    def __str__(self):
        return f'{self.name} from {self.book}'

我想用这个结构返回一个json文件中的所有实例：

[
    {
        "name": 'Dumas', 
        "books": {
            "name": "The count of Montecristo",
            "paragraphs": {
                "name": "paragraph_name_1",
                         },
                          {
                "name": "paragraph_name_2",
                         },
                 {
            "name": "The three Musketeers",
            "paragraphs": {
                "name": "paragraph_name",
                         },
]

我尝试了什么： serializers.py

class AuthorSerializer(serializers.ModelSerializer):

    books = serializers.CharField(source='get_books', read_only=True)

    class Meta:
        model = Author
        fields = ['name', 'books']

这添加了books 键，但值是Book 的字符串表示形式（当然），我如何使值成为Book 的序列化实例？我创建了一个BookSerializer。 注意事项： 我知道我可以通过使用depth = 2 为Paragraph 创建一个序列化程序来创建一个嵌套的json，但这将包括我不想要的字段（如Book 中的pages），并且json 结构将完全不同。

Answer 1

您可以将嵌套序列化器创建为

class ParagraphSerializer(serializers.ModelSerializer):
    class Meta:
        model = Paragraph
        fields = ("name",)


class BookSerializer(serializers.ModelSerializer):
    paragraphs = ParagraphSerializer(source="paragraph_set", many=True, read_only=True)

    class Meta:
        model = Book
        fields = ("name", "paragraphs")


class AuthorSerializer(serializers.ModelSerializer):
    books = BookSerializer(source="book_set", read_only=True, many=True)

    class Meta:
        model = Author
        fields = ['name', 'books']