Question

I have created a Company model and a profile model.

Every User belongs to one company and a company can belong to many users.

Which of the two is the correct way of modelling it?

class Company(models.Model):
    company_name = models.CharField(max_length=50)
    company_code = models.CharField(max_length=40)
    company_email = models.EmailField()

    def save(self, *args, **kwargs):

        if not self.company_code:
            self.company_code = uuid.uuid1()

        super(Company, self).save(*args, **kwargs)

Now the UserProfile is defined like this:

class UserProfile(models.Model):
    # This field is required.
    user = models.OneToOneField(User)
    # Other fields here
    company = models.ManyToManyField(Company)

    #  !!!! OR  !!!!

    company = models.ForeignKey(Company)

Update:

class UserProfile(models.Model):
    user = models.OneToOneField(User)
    company = models.ForeignKey(Company)

    def create_user_profile(self, instance, created, **kwargs):
        if created:
            UserProfile.objects.create(user=instance)

    post_save.connect(create_user_profile, sender=User)

I have now added this bit to UserProfile class also added AUTH_PROFILE_MODULE = 'MyApp.UserProfile' to the settings.

When I do syncdb I get an error message:

>> company = models.ForeignKey(Company)
NameError: name 'Company' is not defined

Answer 1

A ManyToManyField would allow a User to belong to multiple Companys. Based on your spec a ForeignKey would be appropriate.