How to describe m2m triple-join table in model (Django)

Question

My question is pretty much the same as this question, except that ALL relationships should be many-to-many.

I have the following classes in my models.py (somewhat simplified):

class Profile(models.Model):
    # Extending the built in User model  
    user = models.ForeignKey(User, unique=True)  
    birthday = models.DateField()

class Media(models.Model):
    title = models.CharField(max_length=200)
    description = models.TextField(max_length=2000)

class Role(models.Model):
    name = models.CharField(max_length=50)

What I want is a junction table that looks something like this:

CREATE TABLE `media_roles` (
    `media_id` bigint(20) unsigned NOT NULL,
    `profile_id` bigint(20) unsigned NOT NULL,
    `role_id` bigint(20) unsigned NOT NULL
)

• John Doe - Director, Writer, Producer
• Jane Doe - Executive Producer
• ...

This is what I've used so far:

class MediaRole(models.Model):
    media = models.ForeignKey(Media)
    user = models.ForeignKey(Profile)
    role = models.ForeignKey(Role)

But isn't there any better way of doing this, not involving the creation of a separate class in the model?

Answer 1

What about separating the two m2m relationships?

class Profile(models.Model):
    ...
    medias = models.ManyToManyField(Media, related_name='profiles')
    roles = models.ManyToManyField(Role, related_name='profiles')

In this way Django create two association tables for you, and you can utilize the convenient related fields like this:

profile = Profile.objects.get(user=someone)
print profile.medias.all()
print profile.roles.all()