Django manage.py 迁移错误

Question

I've been working on a project for CS50-Web for a while now and I was changing some of my models trying to add a unique attribute to some things. Long story short it wasn't working how I wanted so I went back to how I had it previously and now something is wrong and I can get it to migrate the changes to the model. I don't understand what to do because it was working fine before. Please can someone help I so frustrated and annoyed that I've broken it after so many hours of work. Sorry I know this error code is long but I don't know which part is important.

Error code

Operations to perform:
  Apply all migrations: admin, auth, contenttypes, network, sessions
Running migrations:
  Applying network.0019_alter_follower_user...Traceback (most recent call last):
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\sqlite3\base.py", line 416, in execute
    return Database.Cursor.execute(self, query, params)
sqlite3.IntegrityError: UNIQUE constraint failed: new__network_follower.user_id

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

Traceback (most recent call last):
  File "C:\Users\caitw\Documents\GitHub\CS50-Web\Project-4-Network\project4\manage.py", line 21, in <module>
    main()
  File "C:\Users\caitw\Documents\GitHub\CS50-Web\Project-4-Network\project4\manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\core\management\__init__.py", line 425, in execute_from_command_line
    utility.execute()
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\core\management\__init__.py", line 419, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\core\management\base.py", line 373, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\core\management\base.py", line 417, in execute
    output = self.handle(*args, **options)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\core\management\base.py", line 90, in wrapped
    res = handle_func(*args, **kwargs)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\core\management\commands\migrate.py", line 253, in handle
    post_migrate_state = executor.migrate(
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\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 "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\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 "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\migrations\executor.py", line 236, in apply_migration
    state = migration.apply(state, schema_editor)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\migrations\migration.py", line 125, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\migrations\operations\fields.py", line 225, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\sqlite3\schema.py", line 140, in alter_field
    super().alter_field(model, old_field, new_field, strict=strict)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\base\schema.py", line 620, in alter_field
    self._alter_field(model, old_field, new_field, old_type, new_type,
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\sqlite3\schema.py", line 362, in _alter_field
    self._remake_table(model, alter_field=(old_field, new_field))
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\sqlite3\schema.py", line 285, in _remake_table
    self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\base\schema.py", line 153, in execute
    cursor.execute(sql, params)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\utils.py", line 99, in execute
    return super().execute(sql, params)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\utils.py", line 67, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\utils.py", line 76, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\caitw\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\django\db\backends\sqlite3\base.py", line 416, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: UNIQUE constraint failed: new__network_follower.user_id

I went back to how I had the code before it failed but it doesn't work now

Answer 1

Just try these 3 commands for migrations:

python manage.py makemigrations appname

python manage.py sqlmigrate appname 0001 #This value will generate afte makemigrations. it can be either 0001, 0002 or more.

python manage.py migrate

And see if it solves this error