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
26777	Cannot add foreign key constraint when migrating manytomany field	Ville Säävuori	nobody	"I have a model that looks like


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

    ...

    attendees = models.ManyToManyField(User, blank=True, related_name=""events_attended"")

    ...

    notify_subscriptions = models.ManyToManyField(User, blank=True, related_name=""events_subscribed"")

}}}

when trying to add and migrate notify_subscriptions field I get an `django.db.utils.IntegrityError: (1215, 'Cannot add foreign key constraint')` error. When adding 

{{{ 

'OPTIONS': {
            ""init_command"": ""SET foreign_key_checks = 0;"",
        },
}}}

 to database settings , the error becames: `django.db.utils.OperationalError: (1825, ""Failed to add the foreign key constraint on table 'levan_liveevent_notify_subscriptions'. Incorrect options in FOREIGN KEY constraint 'slipmat/levan_liveevent_noti_liveevent_id_a4871abc_fk_levan_liveevent_id'"")`

the migration file looks like:

{{{

    operations = [
        migrations.AddField(
            model_name='liveevent',
            name='notify_subscriptions',
            field=models.ManyToManyField(blank=True, related_name='events_subscribed', to=settings.AUTH_USER_MODEL),
        ),
    ]

}}}

I'm using MySQL version 5.6.27 and Django version 1.9.7"	Uncategorized	new	Migrations	1.9	Normal				Unreviewed	0	0	0	0	0	0