Opened 10 years ago
Last modified 10 years ago
#22761 new Bug
Migrating from an auto to natural key with foreign model and 'to' FK
Reported by: | jarshwah | Owned by: | nobody |
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Component: | Migrations | Version: | 1.7 |
Severity: | Normal | Keywords: | migrations |
Cc: | Triage Stage: | Accepted | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
I've run into issues with Postgres and Oracle (so I'd assume other backends are affected) not being able to migrate a model from an auto primary key to a natural primary key, where another model has a foreign key that points at the natural.
class Recording(models.Model): some_key = models.PositiveIntegerField(unique=True) class Tag(models.Model): recording = models.ForeignKey(Recording, to_field='some_key') (scratchpad)smeatonj ~/Development/scratchpad $ ./manage.py makemigrations Migrations for 'migrationstest': 0001_initial.py: - Create model Recording - Create model Tag class Migration(migrations.Migration): dependencies = [ ] operations = [ migrations.CreateModel( name='Recording', fields=[ ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)), ('some_key', models.PositiveIntegerField(unique=True)), ], options={ }, bases=(models.Model,), ), migrations.CreateModel( name='Tag', fields=[ ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)), ('recording', models.ForeignKey(to='migrationstest.Recording', to_field=b'some_key')), ], options={ }, bases=(models.Model,), ), ] (scratchpad)smeatonj ~/Development/scratchpad $ ./manage.py migrate Operations to perform: Synchronize unmigrated apps: sessions, admin, scratch, debug_toolbar, sites, auth, aggregation, contenttypes, django_extensions Apply all migrations: migrationstest Synchronizing apps without migrations: Creating tables... Installing custom SQL... Installing indexes... Running migrations: Applying migrationstest.0001_initial... FAKED (scratchpad)smeatonj ~/Development/scratchpad $
Now we change the main model to use a natural key, and remove the to
directive of the foreign key:
# change to natural key class Recording(models.Model): some_key = models.PositiveIntegerField(primary_key=True) class Tag(models.Model): recording = models.ForeignKey(Recording) (scratchpad)smeatonj ~/Development/scratchpad $ ./manage.py makemigrations Migrations for 'migrationstest': 0002_auto_20140604_0806.py: - Remove field id from recording - Alter field some_key on recording class Migration(migrations.Migration): dependencies = [ ('migrationstest', '0001_initial'), ] operations = [ migrations.RemoveField( model_name='recording', name='id', ), migrations.AlterField( model_name='recording', name='some_key', field=models.PositiveIntegerField(serialize=False, primary_key=True), ), ] (scratchpad)smeatonj ~/Development/scratchpad $ ./manage.py migrate Operations to perform: Synchronize unmigrated apps: sessions, admin, scratch, debug_toolbar, sites, auth, aggregation, contenttypes, django_extensions Apply all migrations: migrationstest Synchronizing apps without migrations: Creating tables... Installing custom SQL... Installing indexes... Running migrations: Applying migrationstest.0002_auto_20140604_0806...Traceback (most recent call last): File "./manage.py", line 9, in <module> execute_from_command_line(sys.argv) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/core/management/__init__.py", line 427, in execute_from_command_line utility.execute() File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/core/management/__init__.py", line 419, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/core/management/base.py", line 288, in run_from_argv self.execute(*args, **options.__dict__) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/core/management/base.py", line 337, in execute output = self.handle(*args, **options) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 146, in handle executor.migrate(targets, plan, fake=options.get("fake", False)) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/migrations/executor.py", line 62, in migrate self.apply_migration(migration, fake=fake) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/migrations/executor.py", line 96, in apply_migration migration.apply(project_state, schema_editor) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/migrations/migration.py", line 107, in apply operation.database_forwards(self.app_label, schema_editor, project_state, new_state) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/migrations/operations/fields.py", line 132, in database_forwards schema_editor.alter_field(from_model, from_field, to_field) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/backends/schema.py", line 508, in alter_field "name": constraint_name, File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/backends/schema.py", line 98, in execute cursor.execute(sql, params) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/backends/utils.py", line 81, in execute return super(CursorDebugWrapper, self).execute(sql, params) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/backends/utils.py", line 65, in execute return self.cursor.execute(sql, params) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/utils.py", line 94, in __exit__ six.reraise(dj_exc_type, dj_exc_value, traceback) File "/Users/smeatonj/Development/.virtualenvs/scratchpad/lib/python2.7/site-packages/django/db/backends/utils.py", line 65, in execute return self.cursor.execute(sql, params) django.db.utils.InternalError: cannot drop constraint migrationstest_recording_some_key_key on table migrationstest_recording because other objects depend on it DETAIL: constraint b25f2749e675737f4ae4891ed60d858c on table migrationstest_tag depends on index migrationstest_recording_some_key_key HINT: Use DROP ... CASCADE to drop the dependent objects too.
It blows up in Oracle too:
Traceback (most recent call last): File "/vagrant/venv/lib/python3.3/site-packages/django/db/backends/utils.py", line 65, in execute return self.cursor.execute(sql, params) File "/vagrant/venv/lib/python3.3/site-packages/django/db/backends/oracle/base.py", line 884, in execute return self.cursor.execute(query, self._param_generator(params)) cx_Oracle.DatabaseError: ORA-02273: this unique/primary key is referenced by some foreign keys The above exception was the direct cause of the following exception: Traceback (most recent call last): File "./manage.py", line 10, in <module> execute_from_command_line(sys.argv) File "/vagrant/venv/lib/python3.3/site-packages/django/core/management/__init__.py", line 427, in execute_from_command_line utility.execute() File "/vagrant/venv/lib/python3.3/site-packages/django/core/management/__init__.py", line 419, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "/vagrant/venv/lib/python3.3/site-packages/django/core/management/base.py", line 288, in run_from_argv self.execute(*args, **options.__dict__) File "/vagrant/venv/lib/python3.3/site-packages/django/core/management/base.py", line 337, in execute output = self.handle(*args, **options) File "/vagrant/venv/lib/python3.3/site-packages/django/core/management/commands/migrate.py", line 146, in handle executor.migrate(targets, plan, fake=options.get("fake", False)) File "/vagrant/venv/lib/python3.3/site-packages/django/db/migrations/executor.py", line 62, in migrate self.apply_migration(migration, fake=fake) File "/vagrant/venv/lib/python3.3/site-packages/django/db/migrations/executor.py", line 96, in apply_migration migration.apply(project_state, schema_editor) File "/vagrant/venv/lib/python3.3/site-packages/django/db/migrations/migration.py", line 107, in apply operation.database_forwards(self.app_label, schema_editor, project_state, new_state) File "/vagrant/venv/lib/python3.3/site-packages/django/db/migrations/operations/fields.py", line 132, in database_forwards schema_editor.alter_field(from_model, from_field, to_field) File "/vagrant/venv/lib/python3.3/site-packages/django/db/backends/oracle/schema.py", line 49, in alter_field super(DatabaseSchemaEditor, self).alter_field(model, old_field, new_field, strict) File "/vagrant/venv/lib/python3.3/site-packages/django/db/backends/schema.py", line 508, in alter_field "name": constraint_name, File "/vagrant/venv/lib/python3.3/site-packages/django/db/backends/schema.py", line 98, in execute cursor.execute(sql, params) File "/vagrant/venv/lib/python3.3/site-packages/django/db/backends/utils.py", line 81, in execute return super(CursorDebugWrapper, self).execute(sql, params) File "/vagrant/venv/lib/python3.3/site-packages/django/db/backends/utils.py", line 65, in execute return self.cursor.execute(sql, params) File "/vagrant/venv/lib/python3.3/site-packages/django/db/utils.py", line 94, in __exit__ six.reraise(dj_exc_type, dj_exc_value, traceback) File "/vagrant/venv/lib/python3.3/site-packages/django/utils/six.py", line 549, in reraise raise value.with_traceback(tb) File "/vagrant/venv/lib/python3.3/site-packages/django/db/backends/utils.py", line 65, in execute return self.cursor.execute(sql, params) File "/vagrant/venv/lib/python3.3/site-packages/django/db/backends/oracle/base.py", line 884, in execute return self.cursor.execute(query, self._param_generator(params)) django.db.utils.DatabaseError: ORA-02273: this unique/primary key is referenced by some foreign keys
Change History (4)
comment:1 by , 10 years ago
comment:2 by , 10 years ago
It looks like the primary issue here is the ForeignKey repointing not working correctly with the to_field argument. Not categorising as RB for now as it's a lesser-used feature and nothing in migrations is technically a regression.
comment:3 by , 10 years ago
Component: | Uncategorized → Migrations |
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Triage Stage: | Unreviewed → Accepted |
Type: | Uncategorized → Bug |
comment:4 by , 10 years ago
Version: | 1.7-beta-2 → 1.7 |
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A few extra notes: