id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
33057	Foreign key constraint in m2m tables is not recreated when altering type of referenced primary key on Oracle.	Fabio Sangiovanni	Mariusz Felisiak	"Hi,

I'm experiencing a weird behaviour migrating from Django 3.1.13 to 3.2.6.

With the following setup:

- Python 3.8.10
- PostgreSQL 11.12
- custom user model with `AutoField` pk
- model (also with `AutoField` pk) related to `User` via `ManyToManyField`

upgrading to Django 3.2.6 with `DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'` leads to a DROP of the foreign key constraints on the (implicit) through model.
The field types on the through model referencing the related models get upgraded correctly; only FK constraints go missing.

I've setup a small reproducer at https://github.com/sanjioh/django32fk
Interested tables: `app_pet_owner` and Django owned ones involving the `User` model (`app_user_groups` and `app_user_user_permissions`).

Please let me know if I can be of further help.

Fabio"	Bug	closed	Migrations	3.2	Normal	fixed	oracle		Ready for checkin	1	0	0	0	0	0