1 from django.db import models

     2 

     3 

     4 class Publisher(models.Model):

     5     name = models.CharField(max_length=100)

     6 

     7 class Author(models.Model):

     8     name = models.CharField(max_length=100)

     9 

    10 class Book(models.Model):

    11     name = models.CharField(max_length=100)

    12     authors = models.ManyToManyField(Author, related_name='books')

    13     publisher = models.ForeignKey(Publisher, related_name='books')