迁移

Question

时使用Django Django的1.9例外FieldDoesNotExist。所以我试图迁移我的数据库，但我遇到了这个错误。我花了很多时间试图解决这个问题，并没有取得成功。如果有必要，我可以上传更多的代码。这里是错误：

C:\Users\James\Desktop\James\Work\django\homepgcom>python manage.py migrate 
Operations to perform: 
    Apply all migrations: auth, interface, sessions, admin, contenttypes, userprofile 
Running migrations: 
    Rendering model states... DONE 
    Applying interface.0002_auto_20160107_1635...Traceback (most recent call last): 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\django\db\models\options.py", line 580, in get_field 
return self.fields_map[field_name] 
KeyError: None 
During handling of the above exception, another exception occurred: 
Traceback (most recent call last): 
File "manage.py", line 10, in <module> 
execute_from_command_line(sys.argv) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\django\core\management\__init__.py", line 350, in execute_from_command_line 
utility.execute() 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\core\management\__init__.py", line 342, in execute 
self.fetch_command(subcommand).run_from_argv(self.argv) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\core\management\base.py", line 348, in run_from_argv 
self.execute(*args, **cmd_options) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\core\management\base.py", line 399, in execute 
output = self.handle(*args, **options) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\core\management\commands\migrate.py", line 200, in handle 
executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\migrations\executor.py", line 92, in migrate 
self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\migrations\executor.py", line 121, in _migrate_all_forwards 
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\migrations\executor.py", line 198, in apply_migration 
state = migration.apply(state, schema_editor) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\migrations\migration.py", line 123, in apply 
operation.database_forwards(self.app_label, schema_editor, old_state, project_state) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\migrations\operations\fields.py", line 201, in database_forwards 
schema_editor.alter_field(from_model, from_field, to_field) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\backends\base\schema.py", line 482, in alter_field 
old_db_params, new_db_params, strict) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\backends\sqlite3\schema.py", line 245, in _alter_field 
self._remake_table(model, alter_fields=[(old_field, new_field)]) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\backends\sqlite3\schema.py", line 181, in _remake_table 
self.create_model(temp_model) 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\backends\base\schema.py", line 250, in create_model 
to_column = field.remote_field.model._meta.get_field(field.remote_field.field_name).column 
File "C:\Users\James\AppData\Local\Programs\Python\Python35\lib\site-packages\ 
django\db\models\options.py", line 582, in get_field 
raise FieldDoesNotExist('%s has no field named %r' % (self.object_name, field_name)) 
django.core.exceptions.FieldDoesNotExist: User has no field named None 

非常感谢提前！

Answer 1

关于五分钟发布后，我想出了一个决议。以为我会分享它，以防将来有人遇到这个问题。

1. 删除所有迁移的所有应用
2. 运行所有的应用程序
3. 然后迁移python manage.py migrate

然后一切都应该就好

觉得自己像一个总白痴花了这么多小时试图解决这个问题，哦！

Answer 2

对于任何新来Django的人来说，很容易发现迁移在团队合作环境中存在有线问题。人员流失是修改模型并进行迁移有人做错了并导致问题。如果它在dev env，删除迁移并重做第一步不是问题。

但是如果它在生产env.You不能删除所有的迁移。如果你这样做，你需要确保新的数据库有原始的数据。这将花费大量的时间比修复错误的迁移。

所以我想正确的方法来解决这个问题是检查迁移文件手动运行

python manage.py migrate

时，如果发生错误，找到字段或表造成的问题，然后修改了错误的迁移文件。

如果有一个

django.db.utils.OperationalError: (1050, "Table 'sometable' already exists

Django Table already exist将解决您的问题。

如果有

django.core.exceptions.FieldDoesNotExist: User has no field named None

它意味着你必须删除migrats.AddField或AlterFields。

operations = [ 
    migrations.AddField(
     model_name='user', 
     name='user_current_plan_id', 
     field=models.IntegerField(blank=True, null=True), 
    ), 
] 

如果有

Duplicate column name

您可以通过Duplicate column name

我对其进行修复，一旦发生错误，不是一个问题，而是一个系列的questions..just冷静下来，并通过修改错误的迁移文件来修复它是比删除所有迁移和重新同步db数据更好的方法。