I have been tryed to change a django model by applying and running migrations but I have been getting this error django.db.utils.IntegrityError: UNIQUE constraint failed: new__startup_home_mates.user_id How can this error be fixed? I have already investigated a lot but I have found nothing that fits my situation. I have already tried to use RenameField and AlterField directly from the migrations file and it is still not working maybe I was doing it wrong.
models.py
class Mates(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='usermates', unique=True)
users_requests = models.ManyToManyField(User, related_name="users_requests")
req_bio = models.CharField(max_length=400)
req_image = models.ImageField(upload_to='requestmates_pics', null=True, blank=True, default=False)
traceback
Traceback (most recent call last):
File "manage.py", line 21, in <module>
main()
File "manage.py", line 17, in main
execute_from_command_line(sys.argv)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\__init__.py", line 401, in execute_from_command_line
utility.execute()
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\__init__.py", line 395, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\base.py", line 328, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\base.py", line 369, in execute
output = self.handle(*args, **options)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\base.py", line 83, in wrapped
res = handle_func(*args, **kwargs)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\commands\migrate.py", line 231, in handle
post_migrate_state = executor.migrate(
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\migrations\executor.py", line 117, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\migrations\executor.py", line 147, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\migrations\executor.py", line 245, in apply_migration
state = migration.apply(state, schema_editor)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\migrations\migration.py", line 124, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\migrations\operations\fields.py", line 249, in database_forwards
schema_editor.alter_field(from_model, from_field, to_field)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\sqlite3\schema.py", line 138, in alter_field
super().alter_field(model, old_field, new_field, strict=strict)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\base\schema.py", line 564, in alter_field
self._alter_field(model, old_field, new_field, old_type, new_type,
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\sqlite3\schema.py", line 360, in _alter_field
self._remake_table(model, alter_field=(old_field, new_field))
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\sqlite3\schema.py", line 283, in _remake_table
self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\base\schema.py", line 142, in execute
cursor.execute(sql, params)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 100, in execute
return super().execute(sql, params)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: UNIQUE constraint failed: new__startup_home_mates.user_id
If you need to see more code please let me know:)
You may added a primary key / id with your models later, but previous database does not have it.
If you add new features to models, add default='something', or null=True,blank=True as arguments. So that old database won't need the unique constraints/value