Django modele, Relacje między modelami - 102:

class Book(models.Model):
    title = models.CharField(max_length=100, unique=True)
    author = models.ForeignKey(Author, on_delete=models.CASCADE, related_name="books")
    category = models.ManyToManyField(BookCategory, related_name="books")
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    def __str__(self) -> str:
        return self.title