Django: Does "primary_key=True" also mean "unique"?

Question

Hello i am testing Django authentication and nesting user data. I created a simple MyProfil model for my users. I wanted to test making a custom id and set the primary_key=True as id = models.UUIDField.

models.py

 class MyProfil(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid4, editable=False)
    owner = models.OneToOneField(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    aboutme = models.TextField(max_length=300, blank=True)
    city = models.TextField(max_length=300, blank=True)

---

so far everything works in my favor but i have a question, that i could not answer myself even after reading the django doc.

Question

Does primary_key=True on my id Field also mean unique or do i have to declare it?

Answer 1

Yes. Since a primary key means a value that can uniquely identify an object. In the documentation on the primary_key parameter, we see:

Field.primary_key

If True, this field is the primary key for the model.

If you don’t specify primary_key=True for any field in your model, Django will automatically add an AutoField to hold the primary key, so you don’t need to set primary_key=True on any of your fields unless you want to override the default primary-key behavior. For more, see Automatic primary key fields.

primary_key=True implies null=False and unique=True. Only one primary key is allowed on an object.