How to use UUID

Solution 1:

I'm not sure why you've created a UUID model. You can add the uuid field directly to the Person model.

class Person(models.Model):
    unique_id = models.UUIDField(default=uuid.uuid4, editable=False, unique=True)

Each person should then have a unique id. If you wanted the uuid to be the primary key, you would do:

class Person(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)

Your current code hasn't added a field to the person. It has created a MyUUIDModel instance when you do MyUUIDModel(), and saved it as a class attribute. It doesn't make sense to do that, the MyUUIDModel will be created each time the models.py loads. If you really wanted to use the MyUUIDModel, you could use a ForeignKey. Then each person would link to a different MyUUIDModel instance.

class Person(models.Model):
    ...
    unique_id = models.ForeignKey(MyUUIDModel, unique=True)

However, as I said earlier, the easiest approach is to add the UUID field directly to the person.

Solution 2:

You need to use the class you created as a subclass when declaring your Person model like this:

import uuid
from django.db import models

class MyUUIDModel(models.Model):
  id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)

class Person(MyUUIDModel):
  ...

This way Person becomes a subclass of MyUUIDModel and will inherit its id field definition.

Solution 3:

You can directly add the id field as a UUIDField in the Person model. There is no need for a separate MyUUIDModel.

I think you have confused it with the MyUUIDModel used in the UUIDField example where the id is a UUIDField. You can just use the below code and it will use UUIDs for id.

import uuid
from django.db import models

class Person(models.Model):
    ...
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False) 

Solution 4:

EDIT: Actually I was wrong. It's not possible yet to implement it as DEFAULT_AUTO_FIELD as it has to inherit from IntegerField. Here's the ticket in the django project with feature request to make it possible. Once it's resolved I'll update my answer.

As of Django 3.2, if you want to use uuid as a pk for all your models on a project-wide level, you don't need a generic abstract model anymore. Just define DEFAULT_AUTO_FIELD setting

default value

DEFAULT_AUTO_FIELD = 'django.db.models.AutoField'

so something like this should work

DEFAULT_AUTO_FIELD = 'django.db.models.UUIDField'

Or even better, create your own field.

DEFAULT_AUTO_FIELD = 'project.common.models.CustomUUIDField'

Where you also define uuid type etc.

As seen in the docs, it can also be applied on an app level.

class MyAppConfig(AppConfig):
    default_auto_field = 'project.common.models.CustomUUIDField'