Remaking table with unique constraint crashes on SQLite.

[Mark]

In Django 4.0a1, this model:

class Tag(models.Model):
    name = models.SlugField(help_text="The tag key.")
    value = models.CharField(max_length=150, help_text="The tag value.")

    class Meta:
        ordering = ["name", "value"]
        constraints = [
            models.UniqueConstraint(
                "name",
                "value",
                name="unique_name_value",
            )
        ]

    def __str__(self):
        return f"{self.name}={self.value}"

with these migrations, using sqlite:

class Migration(migrations.Migration):

    initial = True

    dependencies = [
    ]

    operations = [
        migrations.CreateModel(
            name='Tag',
            fields=[
                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('name', models.SlugField(help_text='The tag key.')),
                ('value', models.CharField(help_text='The tag value.', max_length=200)),
            ],
            options={
                'ordering': ['name', 'value'],
            },
        ),
        migrations.AddConstraint(
            model_name='tag',
            constraint=models.UniqueConstraint(django.db.models.expressions.F('name'), django.db.models.expressions.F('value'), name='unique_name_value'),
        ),
    ]


class Migration(migrations.Migration):

    dependencies = [
        ('myapp', '0001_initial'),
    ]

    operations = [
        migrations.AlterField(
            model_name='tag',
            name='value',
            field=models.CharField(help_text='The tag value.', max_length=150),
        ),
    ]

raises this error:

manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, myapp, sessions
Running migrations:
  Applying myapp.0002_alter_tag_value...python-BaseException
Traceback (most recent call last):
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\sqlite3\base.py", line 416, in execute
    return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: the "." operator prohibited in index expressions

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\core\management\base.py", line 373, in run_from_argv
    self.execute(*args, **cmd_options)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\core\management\base.py", line 417, in execute
    output = self.handle(*args, **options)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\core\management\base.py", line 90, in wrapped
    res = handle_func(*args, **kwargs)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\core\management\commands\migrate.py", line 253, in handle
    post_migrate_state = executor.migrate(
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\migrations\executor.py", line 126, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\migrations\executor.py", line 156, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\migrations\executor.py", line 236, in apply_migration
    state = migration.apply(state, schema_editor)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\migrations\migration.py", line 125, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\migrations\operations\fields.py", line 225, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\sqlite3\schema.py", line 140, in alter_field
    super().alter_field(model, old_field, new_field, strict=strict)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\base\schema.py", line 618, in alter_field
    self._alter_field(model, old_field, new_field, old_type, new_type,
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\sqlite3\schema.py", line 362, in _alter_field
    self._remake_table(model, alter_field=(old_field, new_field))
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\sqlite3\schema.py", line 303, in _remake_table
    self.execute(sql)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\base\schema.py", line 151, in execute
    cursor.execute(sql, params)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\utils.py", line 98, in execute
    return super().execute(sql, params)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\utils.py", line 66, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\utils.py", line 75, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "D:\Projects\Development\sqliteerror\.venv\lib\site-packages\django\db\backends\sqlite3\base.py", line 416, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: the "." operator prohibited in index expressions

[Mariusz Felisiak]

Thanks for the report.

Regression in 3aa545281e0c0f9fac93753e3769df9e0334dbaa.

[Hannes Ljungberg]

Thanks for the report! Looks like we don't check if an alias is set on the Col before we update it to new_table in Expressions.rename_table_references when running _remake_table.

[Hannes Ljungberg]

PR: ​https://github.com/django/django/pull/14997

Not really sure if we need a backport to 3.2 but feels like this would create issues for non-unique functional indexes on SQLite as well.

[Mariusz Felisiak]

Not really sure if we need a backport to 3.2 but feels like this would create issues for non-unique functional indexes on SQLite as well.

Good catch, it's a bug in 83fcfc9ec8610540948815e127101f1206562ead.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 86971c4:

Fixed #33194 -- Fixed migrations when altering a field with functional indexes/unique constraints on SQLite.

This adjusts Expressions.rename_table_references() to only update alias
when needed.

Regression in 83fcfc9ec8610540948815e127101f1206562ead.

Co-authored-by: Simon Charette <charettes@…>

[Mariusz Felisiak <felisiak.mariusz@…>]

In 00aa3e0b:

[4.0.x] Fixed #33194 -- Fixed migrations when altering a field with functional indexes/unique constraints on SQLite.

This adjusts Expressions.rename_table_references() to only update alias
when needed.

Regression in 83fcfc9ec8610540948815e127101f1206562ead.

Co-authored-by: Simon Charette <charettes@…>

Backport of 86971c40909430a798e4e55b140004c4b1fb02ff from main

[Mariusz Felisiak <felisiak.mariusz@…>]

In f5802a21:

[3.2.x] Fixed #33194 -- Fixed migrations when altering a field with functional indexes on SQLite.

This adjusts Expressions.rename_table_references() to only update alias
when needed.

Regression in 83fcfc9ec8610540948815e127101f1206562ead.

Co-authored-by: Simon Charette <charettes@…>

Backport of 86971c40909430a798e4e55b140004c4b1fb02ff from main.