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
33709	Primary key of m2m tables is not migrated to BigAutoField	Jeremy Lainé	nobody	"I am trying to upgrade an existing application's models to use only ""bigint"" primary keys on postgresql. To do this I changed DEFAULT_AUTO_FIELD to BigAutoField, generated the migrations then applied them.

The tables for my explicitly defined models get upgraded correctly. The  many-to-many intermediate tables on the other hand still have an ""integer"" primary key, with the 32bit limit I'm trying to avoid.

The following model are sufficient to reproduce the issue:

{{{
class Book(models.Model):
    name = models.CharField(max_length=255)
    tags = models.ManyToManyField(""Tag"")


class Tag(models.Model):
    name = models.CharField(max_length=255)
}}}

The resulting schema for the testapp_book_tags looks like:

{{{
test=> \d testapp_book_tags;
                             Table ""public.testapp_book_tags""
 Column  |  Type   | Collation | Nullable |                    Default                    
---------+---------+-----------+----------+-----------------------------------------------
 id      | integer |           | not null | nextval('testapp_book_tags_id_seq'::regclass)
 book_id | bigint  |           | not null | 
 tag_id  | bigint  |           | not null |
}}}"	New feature	closed	Database layer (models, ORM)	3.2	Normal	duplicate			Unreviewed	0	0	0	0	0	0