#27940 closed Bug (duplicate)
Migrations fail when when a model's parent class is changed to abstract -- Wrong SQL being generated
Reported by: | Sawan Vithlani | Owned by: | nobody |
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Component: | Migrations | Version: | 1.10 |
Severity: | Normal | Keywords: | SQLite migrations abstract inheritance |
Cc: | Triage Stage: | Unreviewed | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description (last modified by )
Consider the following class hierarchy:
class TestCase(models.Model): name = models.CharField(max_length=10) class TerminalTest(TestCase): pass class BrowserTest(TestCase): pass $ ./manage.py makemigrations testbed Migrations for 'testbed': testbed\migrations\0001_initial.py: - Create model TestCase - Create model BrowserTest - Create model TerminalTest $ ./manage.py migrate testbed Operations to perform: Apply all migrations: testbed Running migrations: Applying testbed.0001_initial... OK
Now we want to make the parent an abstract class:
class TestCase(models.Model): name = models.CharField(max_length=10) class Meta: abstract = True class TerminalTest(TestCase): pass class BrowserTest(TestCase): pass ./manage.py makemigrations testbed You are trying to add a non-nullable field 'id' to browsertest without a default; we can't do that (the database needs something to populate existing rows). Please select a fix: 1) Provide a one-off default now (will be set on all existing rows with a null value for this column) 2) Quit, and let me add a default in models.py Select an option: 1 Please enter the default value now, as valid Python The datetime and django.utils.timezone modules are available, so you can do e.g. timezone.now Type 'exit' to exit this prompt >>> 1 You are trying to add a non-nullable field 'name' to browsertest without a default; we can't do that (the database needs something to populate existing rows). Please select a fix: 1) Provide a one-off default now (will be set on all existing rows with a null value for this column) 2) Quit, and let me add a default in models.py Select an option: 1 Please enter the default value now, as valid Python The datetime and django.utils.timezone modules are available, so you can do e.g. timezone.now Type 'exit' to exit this prompt >>> ' ' You are trying to add a non-nullable field 'id' to terminaltest without a default; we can't do that (the database needs something to populate existing rows). Please select a fix: 1) Provide a one-off default now (will be set on all existing rows with a null value for this column) 2) Quit, and let me add a default in models.py Select an option: 1 Please enter the default value now, as valid Python The datetime and django.utils.timezone modules are available, so you can do e.g. timezone.now Type 'exit' to exit this prompt >>> 1 You are trying to add a non-nullable field 'name' to terminaltest without a default; we can't do that (the database needs something to populate existing rows). Please select a fix: 1) Provide a one-off default now (will be set on all existing rows with a null value for this column) 2) Quit, and let me add a default in models.py Select an option: 1 Please enter the default value now, as valid Python The datetime and django.utils.timezone modules are available, so you can do e.g. timezone.now Type 'exit' to exit this prompt >>> ' ' Migrations for 'testbed': testbed\migrations\0002_auto_20170315_1711.py: - Remove field testcase_ptr from browsertest - Remove field testcase_ptr from terminaltest - Add field id to browsertest - Add field name to browsertest - Add field id to terminaltest - Add field name to terminaltest - Delete model TestCase $ ./manage.py migrate testbed Operations to perform: Apply all migrations: testbed Running migrations: Applying testbed.0002_auto_20170315_1600...Traceback (most recent call last): File "C:\my-venv\lib\site-packages\django\db\backends\utils.py", line 64, in execute return self.cursor.execute(sql, params) File "C:\my-venv\lib\site-packages\django\db\backends\sqlite3\base.py", line 337, in execute return Database.Cursor.execute(self, query, params) sqlite3.OperationalError: near ")": syntax error 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 "C:\my-venv\lib\site-packages\django\core\management\__init__.py", line 367, in execute_from_command_line utility.execute() File "C:\my-venv\lib\site-packages\django\core\management\__init__.py", line 359, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "C:\my-venv\lib\site-packages\django\core\management\base.py", line 294, in run_from_argv self.execute(*args, **cmd_options) File "C:\my-venv\lib\site-packages\django\core\management\base.py", line 345, in execute output = self.handle(*args, **options) File "C:\my-venv\lib\site-packages\django\core\management\commands\migrate.py", line 204, in handle fake_initial=fake_initial, File "C:\my-venv\lib\site-packages\django\db\migrations\executor.py", line 115, in migrate state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial) File "C:\my-venv\lib\site-packages\django\db\migrations\executor.py", line 145, in _migrate_all_forwards state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial) File "C:\my-venv\lib\site-packages\django\db\migrations\executor.py", line 244, in apply_migration state = migration.apply(state, schema_editor) File "C:\my-venv\lib\site-packages\django\db\migrations\migration.py", line 129, in apply operation.database_forwards(self.app_label, schema_editor, old_state, project_state) File "C:\my-venv\lib\site-packages\django\db\migrations\operations\fields.py", line 147, in database_forwards schema_editor.remove_field(from_model, from_model._meta.get_field(self.name)) File "C:\my-venv\lib\site-packages\django\db\backends\sqlite3\schema.py", line 249, in remove_field self._remake_table(model, delete_fields=[field]) File "C:\my-venv\lib\site-packages\django\db\backends\sqlite3\schema.py", line 199, in _remake_table self.quote_name(model._meta.db_table), File "C:\my-venv\lib\site-packages\django\db\backends\base\schema.py", line 112, in execute cursor.execute(sql, params) File "C:\my-venv\lib\site-packages\django\db\backends\utils.py", line 79, in execute return super(CursorDebugWrapper, self).execute(sql, params) File "C:\my-venv\lib\site-packages\django\db\backends\utils.py", line 64, in execute return self.cursor.execute(sql, params) File "C:\my-venv\lib\site-packages\django\db\utils.py", line 94, in __exit__ six.reraise(dj_exc_type, dj_exc_value, traceback) File "C:\my-venv\lib\site-packages\django\utils\six.py", line 685, in reraise raise value.with_traceback(tb) File "C:\my-venv\lib\site-packages\django\db\backends\utils.py", line 64, in execute return self.cursor.execute(sql, params) File "C:\my-venv\lib\site-packages\django\db\backends\sqlite3\base.py", line 337, in execute return Database.Cursor.execute(self, query, params) django.db.utils.OperationalError: near ")": syntax error
The problem is that the SQL query generated by this (code block) in django/db/backends/sqlite3/schema.py:
# Copy data from the old table into the new table field_maps = list(mapping.items()) self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % ( self.quote_name(temp_model._meta.db_table), ', '.join(self.quote_name(x) for x, y in field_maps), ', '.join(y for x, y in field_maps), self.quote_name(model._meta.db_table), ))
reads:
'INSERT INTO "testbed_browsertest" () SELECT FROM "testbed_browsertest__old" '
This is a wrong query in SQLite syntax. Correct query is:
'INSERT INTO "testbed_browsertest" SELECT * FROM "testbed_browsertest__old" '
This has been verified by monkey-patching the query generated and having the migration move to the next stage -- where it fails for a completely different reason (nothing to do with SQL). See bug 27941
Change History (4)
comment:1 by , 8 years ago
Summary: | Migrations fail when when Models parent class is changed to abstract -- Wrong SQL being generated → Migrations fail when when a model's parent class is changed to abstract -- Wrong SQL being generated |
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comment:2 by , 8 years ago
Description: | modified (diff) |
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comment:3 by , 8 years ago
Description: | modified (diff) |
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comment:4 by , 8 years ago
Resolution: | → duplicate |
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Status: | new → closed |
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Please see bug 27941 for related bug.