Django Custom user Model migration path

steps.md

Steps to migrate existing Django app to new user model

This all refers to PostgreSQL, on other databases it will probably be different.

1. Create the new User model as an exact copy of django.contrib.auth.models.User (we assume it will be user.User then)

2. Create the migrations and commit them

3. Run the following SQL to simulate that the migration has run

   SELECT * FROM django_migrations_id_seq;
   ALTER TABLE django_migrations DROP CONSTRAINT django_migrations_pkey;
   UPDATE django_migrations SET id = id + 1;
   ALTER TABLE django_migrations ADD CONSTRAINT django_migrations_pkey PRIMARY KEY (id);
   INSERT INTO django_migrations (id,app, name, applied) VALUES
      (1, 'user', '0001_initial', '1970-01-01 00:00:00.000000+00');
   ALTER SEQUENCE django_migrations_id_seq RESTART WITH <<<fill-in>>>;

This leads to issues with the next migrations.

It fails with the unfortunate situation that the migration will be applied but not logged. This can be fixed like this:

INSERT INTO django_migrations (app,name,applied) VALUES ('oauth2_provider', '0001_initial', now());