How is the many-to-many relationship managed in Django ORM?

In Django ORM, a many-to-many relationship is implemented through a special intermediate table that stores pairs of keys from related models.

By default, Django automatically creates this table unless a custom model for the relationship is explicitly specified.

Example:

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)
    authors = models.ManyToManyField(Author)

Here, authors is a many-to-many field that creates a table with two columns: book_id and author_id.

You can also define your own intermediate model if you need to add additional fields:

class Authorship(models.Model):
    author = models.ForeignKey(Author, on_delete=models.CASCADE)
    book = models.ForeignKey(Book, on_delete=models.CASCADE)
    role = models.CharField(max_length=50)  # for example, "editor"

class Book(models.Model):
    title = models.CharField(max_length=100)
    authors = models.ManyToManyField(Author, through='Authorship')

Thus, Django ORM manages the many-to-many relationship through an intermediate table and provides a convenient API for adding, removing, and querying related objects.