#25313: Document how to migrate from a built-in User model to a custom User
model
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Reporter: Carl Meyer | Owner: nobody
Type: New feature | Status: new
Component: Documentation | Version: 1.8
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
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Comment (by mikob):
Thank you Aymeric et. al for these steps, they worked for me. I made one
silly mistake in 1. not creating the user properly. For other people who
might also get stuck on this, here is what your User model should look
like for step 1:
{{{
class User(AbstractUser):
class Meta:
db_table = 'auth_user'
}}}
Replying to [comment:12 Dustin Torres]:
> Replying to [comment:2 Aymeric Augustin]:
> > I did it at least twice. Unfortunately I don't remember all the
details.
> >
> > I think a reasonable procedure is:
> >
> > 1. Create a custom user model identical to `auth.User`, call it `User`
(so many-to-many tables keep the same name) and set `db_table='auth_user'`
(so it uses the same table)
> > 2. Throw away all your migrations
> > 3. Recreate a fresh set of migrations
> > 4. Sacrifice a chicken, perhaps two if you're anxious; also make a
backup of your database
> > 5. Truncate the `django_migrations` table
> > 6. Fake-apply the new set of migrations
> > 7. Unset `db_table`, make other changes to the custom model, generate
migrations, apply them
> >
> > It is highly recommended to do this on a database that enforces
foreign key constraints. Don't try this on SQLite on your laptop and
expect it to work on Postgres on the servers!
>
> Thanks for this, I followed your steps and Justin Smith's notes and want
to add one more:
>
> 6b. Any model that has a link to ContentType may be linked to the now
stale auth.User content type. I went through and updated all models that
were pointing to auth.User content type to my new User model. You can find
out what type of objects would be removed due to cascading delete of the
stale auth.User content type by running `manage.py
remove_stale_contenttypes` **and make sure to answer NO** when asked if
you want to proceed.
>
> If you don't unset `db_table` the above step may be optional since the
content type lookup will use auth.User model which will still have a valid
database table (although I don't recommend relying on this).
--
Ticket URL: <https://code.djangoproject.com/ticket/25313#comment:13>
Django <https://code.djangoproject.com/>
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