在 Django 中无缘无故地出现“重复列名”错误

Question

我在这里和通过 Google 进行了查看，但没有发现任何似乎可以描述我所看到的内容。我将 Django 1.7 与 Python 3.4 一起使用。

ETA：我使用的是 MySQL 5.6.17

我有以下模型（省略了不相关的字段）：

class Location(models.Model):
    location_type = models.CharField(max_length=5,
                                     choices=constants.LocationTypes.LOCATION_CHOICES
                                     )
    parent = models.ForeignKey("Location", blank=True, null=True, related_name='location_parent')
    room = models.ForeignKey("Location", blank=True, null=True, related_name='location_room')

models.py 中除注释外，没有其他“房间”实例。

在我添加房间字段之前它工作正常（同时将related _name 添加到parent）。现在，当我尝试运行迁移时，我得到以下信息：

File "C:\Python34\lib\site-packages\django\db\backends\utils.py", line 65, in execute return self.cursor.execute(sql, params)
File "C:\Python34\lib\site-packages\django\db\backends\mysql\base.py", line 128, in execute return self.cursor.execute(query, args)
File "C:\Python34\lib\site-packages\pymysql\cursors.py", line 132, in execute result = self._query(query)
File "C:\Python34\lib\site-packages\pymysql\cursors.py", line 271, in _query conn.query(q)
File "C:\Python34\lib\site-packages\pymysql\connections.py", line 726, in query self._affected_rows = self._read_query_result(unbuffered=unbuffered)
File "C:\Python34\lib\site-packages\pymysql\connections.py", line 861, in _read_query_result result.read()
File "C:\Python34\lib\site-packages\pymysql\connections.py", line 1064, in read first_packet = self.connection._read_packet()
File "C:\Python34\lib\site-packages\pymysql\connections.py", line 826, in _read_packet packet.check_error()
File "C:\Python34\lib\site-packages\pymysql\connections.py", line 370, in check_error raise_mysql_exception(self._data)
File "C:\Python34\lib\site-packages\pymysql\err.py", line 116, in raise_mysql_exception _check_mysql_exception(errinfo)
File "C:\Python34\lib\site-packages\pymysql\err.py", line 112, in _check_mysql_exception raise InternalError(errno, errorvalue)
pymysql.err.InternalError: (1060, "Duplicate column name 'room_id'")

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

Traceback (most recent call last):
  File "C:/Users/Phoenix/PycharmProjects/gamecon/manage.py", line 10, in <module> execute_from_command_line(sys.argv)
  File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line 385, in execute_from_command_line utility.execute()
  File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line 377, in execute self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python34\lib\site-packages\django\core\management\base.py", line 288, in run_from_argv self.execute(*args, **options.__dict__)
  File "C:\Python34\lib\site-packages\django\core\management\base.py", line 338, in execute output = self.handle(*args, **options)
  File "C:\Python34\lib\site-packages\django\core\management\commands\migrate.py", line 160, in handle executor.migrate(targets, plan, fake=options.get("fake", False))
  File "C:\Python34\lib\site-packages\django\db\migrations\executor.py", line 63, in migrate self.apply_migration(migration, fake=fake)
  File "C:\Python34\lib\site-packages\django\db\migrations\executor.py", line 97, in apply_migration migration.apply(project_state, schema_editor)
  File "C:\Python34\lib\site-packages\django\db\migrations\migration.py", line 107, in apply operation.database_forwards(self.app_label, schema_editor, project_state, new_state)
  File "C:\Python34\lib\site-packages\django\db\migrations\operations\fields.py", line 37, in database_forwards field,
  File "C:\Python34\lib\site-packages\django\db\backends\mysql\schema.py", line 42, in add_field super(DatabaseSchemaEditor, self).add_field(model, field)
  File "C:\Python34\lib\site-packages\django\db\backends\schema.py", line 390, in add_field self.execute(sql, params)
  File "C:\Python34\lib\site-packages\django\db\backends\schema.py", line 99, in execute cursor.execute(sql, params)
  File "C:\Python34\lib\site-packages\django\db\backends\utils.py", line 81, in execute return super(CursorDebugWrapper, self).execute(sql, params)
  File "C:\Python34\lib\site-packages\django\db\backends\utils.py", line 65, in execute return self.cursor.execute(sql, params)
  File "C:\Python34\lib\site-packages\django\db\utils.py", line 94, in __exit__ six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "C:\Python34\lib\site-packages\django\utils\six.py", line 549, in reraise raise value.with_traceback(tb)
  File "C:\Python34\lib\site-packages\django\db\backends\utils.py", line 65, in execute return self.cursor.execute(sql, params)
  File "C:\Python34\lib\site-packages\django\db\backends\mysql\base.py", line 128, in execute return self.cursor.execute(query, args)
  File "C:\Python34\lib\site-packages\pymysql\cursors.py", line 132, in execute result = self._query(query)
  File "C:\Python34\lib\site-packages\pymysql\cursors.py", line 271, in _query conn.query(q)
  File "C:\Python34\lib\site-packages\pymysql\connections.py", line 726, in query self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "C:\Python34\lib\site-packages\pymysql\connections.py", line 861, in _read_query_result result.read()
  File "C:\Python34\lib\site-packages\pymysql\connections.py", line 1064, in read first_packet = self.connection._read_packet()
  File "C:\Python34\lib\site-packages\pymysql\connections.py", line 826, in _read_packet packet.check_error()
  File "C:\Python34\lib\site-packages\pymysql\connections.py", line 370, in check_error raise_mysql_exception(self._data)
  File "C:\Python34\lib\site-packages\pymysql\err.py", line 116, in raise_mysql_exception  _check_mysql_exception(errinfo)
  File "C:\Python34\lib\site-packages\pymysql\err.py", line 112, in _check_mysql_exception raise InternalError(errno, errorvalue)
django.db.utils.InternalError: (1060, "Duplicate column name 'room_id'")

有人可以告诉我我在这里缺少什么吗？

Answer 1

从评论中回答

如果你在模型本身上做 ForeignKey，你应该这样做

models.ForeignKey("self", blank=True, null=True, related_name='location_parent')