Dans le module models.py d'une application :

from django.db import models
 
class Author(models.Model):
    name = models.CharField(max_length=100, unique=True)
 
class Book(models.Model):
    title = models.CharField(max_length=200)
    quantity = models.IntegerField(default = 1)
    author = models.ForeignKey(Author, on_delete=models.DO_NOTHING)

Paramètres :

Types :