Django Rest framework中序列化A表时怎么获取B表的数据

from django.db import models


# Create your models here.


class Author(models.Model):
    """
    图书作者表
    """
    name = models.CharField('作者姓名', max_length=20)
    age = models.SmallIntegerField('年龄')

    def __str__(self):
        return self.name


class Book(models.Model):
    """
    图书表
    """
    book_name = models.CharField('图书名称', max_length=100)
    author = models.ForeignKey(Author, related_name='author_book')
    publish_time = models.DateTimeField('出版时间', auto_now_add=True)

    def __str__(self):
        return self.book_name

from rest_framework import generics, serializers
from ..models import Author


class AuthorSerializer(serializers.ModelSerializer):

    class Meta:
        model = Author
        fields = '__all__'



class AuthorList(generics.ListAPIView):
    """
    查询所有作者信息，及其对应编写的书籍
    """
    queryset = Author.objects.all()
    serializer_class = AuthorSerializer

class AuthorSerializer(serializers.ModelSerializer):
    # 该字段信息通过下方的get_books方法获取数据
    books = serializers.SerializerMethodField()

    class Meta:
        model = Author
        fields = '__all__'

    # 方法名称必须与上面定义的序列化字段一致，格式为："get_自定义字段名"
    def get_books(self, author_obj):
        # 通过book模型中的author字段的related_name反查出作者对应的图书集合
        book_query_set = author_obj.author_book.all()
        # 遍历图书集合获取图书的名称和出版时间，并返回
        return {'count': book_query_set.count(),
                "data": [{'name': book_obj.book_name, 'publish_time': book_obj.publish_time} for
                         book_obj in book_query_set]}