Set multiple fields to a User as a ForeignKey

Using Django Using the ORM
1

How do I set multiple fields to a User as a ForeignKey ?

manager = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)
tester = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)
developer = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)
designer = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)
team_lead = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)

I get :

ERRORS:
service_order.ServiceOrder.manager: (fields.E304) Reverse accessor ‘User.serviceorder_set’ for ‘service_order.ServiceOrder.manager’ clashes with reverse accessor for ‘service_order.ServiceOrder.db_user’.

2

It seems I have to give , related_name='manager'

manager = models.ForeignKey(User, null=True, on_delete=models.SET_NULL, related_name='manager')
tester = models.ForeignKey(User, null=True, on_delete=models.SET_NULL, related_name='tester')
developer = models.ForeignKey(User, null=True, on_delete=models.SET_NULL, related_name='developer')
designer = models.ForeignKey(User, null=True, on_delete=models.SET_NULL, related_name='designer')
team_lead = models.ForeignKey(User, null=True, on_delete=models.SET_NULL, related_name='team_lead')
3

And, if you want your database tables normalized, you could implement it this way:

members = models.ManyToManyField(User, through=MemberRole)

with:

class MemberRole(models.Model):
    team = models.ForeignKey('Team', on_delete=models.CASCADE)  # Whatever the model is above
    person = models.ForeignKey('User', on_delete=models.CASCADE)
    role = models.ForeignKey('RoleName', on_delete=models.PROTECT)

class RoleName(models.Model):
    name = models.CharField(max_length=20) # Optionally, primary_key=True