#28309: Migration bug in related_name for ManyToManyField with self
-------------------------------------+-------------------------------------
Reporter: Ahmed Mohamed | Owner: nobody
Type: Bug | Status: new
Component: Migrations | Version: 1.11
Severity: Normal | Resolution:
Keywords: ManyToManyField | Triage Stage:
self | Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Old description:
> The related_name is not set correctly on ManyToManyField when it is
> related with 'self'. When I use the model name explicitly, it is set
> correctly.
>
> {{{
> class Model1(models.Model):
> children = models.ManyToManyField('self', blank=True,
> related_name='parents')
>
> class Model2(models.Model):
> children = models.ManyToManyField('self', blank=True,
> related_name='parents')
> }}}
>
> {{{
> migrations.CreateModel(
> name='Model1',
> fields=[
> ('id', models.AutoField(auto_created=True, primary_key=True,
> serialize=False, verbose_name='ID')),
> ('children', models.ManyToManyField(blank=True,
> related_name='_model1_children_+', to='raftprot.Model1')),
> ],
> ),
> migrations.CreateModel(
> name='Model2',
> fields=[
> ('id', models.AutoField(auto_created=True, primary_key=True,
> serialize=False, verbose_name='ID')),
> ('children', models.ManyToManyField(blank=True,
> related_name='parents', to='raftprot.Model2')),
> ],
> ),
> }}}
New description:
The related_name is not set correctly on ManyToManyField when it is
related with 'self'. When I use the model name explicitly, it is set
correctly.
{{{
class Model1(models.Model):
children = models.ManyToManyField('self', blank=True)
class Model2(models.Model):
children = models.ManyToManyField('self', blank=True,
related_name='parents')
}}}
{{{
migrations.CreateModel(
name='Model1',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True,
serialize=False, verbose_name='ID')),
('children', models.ManyToManyField(blank=True,
related_name='_model1_children_+', to='raftprot.Model1')),
],
),
migrations.CreateModel(
name='Model2',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True,
serialize=False, verbose_name='ID')),
('children', models.ManyToManyField(blank=True,
related_name='parents', to='raftprot.Model2')),
],
),
}}}
--
Comment (by Tim Graham):
I've edited the ticket description as I think you meant, please correct it
if needed. If the unexpected output in the migration is
`related_name='_model1_children_+'`, that's coming from
[https://github.com/django/django/blob/a6b5321ce997b899e540bb427cca98cb2b93a106/django/db/models/fields/related.py#L1531-L1546
ManyToManyField.contribute_to_class()]. I'm uncertain if this is a bug.
Can you please clarify?
--
Ticket URL: <https://code.djangoproject.com/ticket/28309#comment:2>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/067.2d26ec44ba20835577d7afe4ce21b1f9%40djangoproject.com.
For more options, visit https://groups.google.com/d/optout.
