Django查询多对一关系，没有外键关系的实例

from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=100)

class Book(models.Model):
    title = models.CharField(max_length=100)
    author_name = models.CharField(max_length=100)

from django.db.models import Count

authors = Author.objects.annotate(book_count=Count('book'))

{% for author in authors %}
    <p>{{ author.name }} 的书籍数量为：{{ author.book_count }}</p>
{% endfor %}