AlterOrderWithRespectTo() with ForeignKey crash when _order is included in Index().

[KyuJoo Han]

    class Meta:
        db_table = 'look_image'
        order_with_respect_to = 'look'
        indexes = [
            models.Index(fields=['look', '_order']),
            models.Index(fields=['created_at']),
            models.Index(fields=['updated_at']),
        ]

migrations.CreateModel(
            name='LookImage',
            fields=[
                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('look', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='images', to='posts.Look', verbose_name='LOOK')),
                ('image_url', models.URLField(blank=True, max_length=10000, null=True)),
                ('image', models.ImageField(max_length=2000, upload_to='')),
                ('deleted', models.DateTimeField(editable=False, null=True)),
                ('created_at', models.DateTimeField(auto_now_add=True)),
                ('updated_at', models.DateTimeField(auto_now=True)),
            ],
        ),
        migrations.AddIndex(
            model_name='lookimage',
            index=models.Index(fields=['look', '_order'], name='look_image_look_id_eaff30_idx'),
        ),
        migrations.AddIndex(
            model_name='lookimage',
            index=models.Index(fields=['created_at'], name='look_image_created_f746cf_idx'),
        ),
        migrations.AddIndex(
            model_name='lookimage',
            index=models.Index(fields=['updated_at'], name='look_image_updated_aceaf9_idx'),
        ),
        migrations.AlterOrderWithRespectTo(
            name='lookimage',
            order_with_respect_to='look',
        ),

I added orders_with_respect_to in new model class's Meta class and also made index for '_order' field by combining with other field. And a new migration file based on the model looks like the code above.

The problem is operation AlterOrderWithRespectTo after AddIndex of '_order' raising error because '_order' field had not been created yet.

It seems to be AlterOrderWithRespectTo has to proceed before AddIndex of '_order'.

[Mariusz Felisiak]

Thanks for this report. IMO order_with_respect_to should be included in CreateModel()'s options, I'm not sure why it is in a separate operation when it refers to a ForeignKey.

[Iuri de Silvio]

I reproduced the issue adding order_with_respect_to and indexes = [models.Index(fields='_order')] at the same time to an existent model.

class Meta:
    order_with_respect_to = 'foo'
    indexes = [models.Index(fields='_order')]

A small broken test: ​https://github.com/iurisilvio/django/commit/5c6504e67f1d2749efd13daca440dfa54708a4b2

I'll try to fix the issue, but I'm not sure the way to fix it. Can we reorder autodetected migrations?

[Mariusz Felisiak <felisiak.mariusz@…>]

In 366a93f:

Refs #31831 -- Added autodector test for unique/index_together on _order field.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 58a336a6:

Fixed #31831 -- Fixed migration operations ordering when adding order_with_respect_to and constraints/indexes.