text: from django.db import models
  
  # Create your models here.
  
  
  class BookInfo(models.Model):
      # Id
      name = models.CharField(max_length=10)
  
      def __str__(self):
          return self.name
  
  
  class PeopleInfo(models.Model):
      name = models.CharField(max_length=10)
      gender = models.BooleanField()
      # 外健约束：人物属于那本书
      book = models.ForeignKey(BookInfo, on_delete=models.CASCADE)
  