Question

我将Stores模型从products应用转移到新stores应用的步骤。 products.Product和pages.Page都有FK到stores.Store。

使用./manage.py startapp stores
将类从旧模型移到新模型.py
更新了对Store的引用（旧的迁移脚本除外，导致它在具有类似错误的makemigrations期间失败）
在模型类中添加了指向旧表名称位置的元数据（见下文）
在浏览器中测试过的网络应用，工作正常
使用./manage.py makemigrations
尝试应用迁移./manage.py migrate，但是在第3个模型Page和应用程序参考Store时爆炸了FK。

移动的模型：

class Store(models.Model):
    class Meta:
        db_table = 'products_store'
    ...

参考文献破损的模型：

from stores.models import Store
...
class Page(TimeStampedModel):
    ...
    store = models.ForeignKey(Store, related_name='pages', null=True)

破碎：

Running migrations:
  Applying pages.0007_auto_20150112_0321...Traceback (most recent call last):
  File "./manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/john/.venv/myproject/lib/python2.7/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "/Users/john/.venv/myproject/lib/python2.7/site-packages/django/core/management/__init__.py", line 377, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/john/.venv/myproject/lib/python2.7/site-packages/django/core/management/base.py", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/Users/john/.venv/myproject/lib/python2.7/site-packages/django/core/management/base.py", line 338, in execute
    output = self.handle(*args, **options)
  File "/Users/john/.venv/myproject/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 161, in handle
    executor.migrate(targets, plan, fake=options.get("fake", False))
  File "/Users/john/.venv/myproject/lib/python2.7/site-packages/django/db/migrations/executor.py", line 68, in migrate
    self.apply_migration(migration, fake=fake)
  File "/Users/john/.venv/myproject/lib/python2.7/site-packages/django/db/migrations/executor.py", line 96, in apply_migration
    if self.detect_soft_applied(migration):
  File "/Users/john/.venv/myproject/lib/python2.7/site-packages/django/db/migrations/executor.py", line 140, in detect_soft_applied
    apps = project_state.render()
  File "/Users/john/.venv/myproject/lib/python2.7/site-packages/django/db/migrations/state.py", line 94, in render
    raise ValueError(msg.format(field=operations[0][1], model=lookup_model))
ValueError: Lookup failed for model referenced by field pages.Page.store: stores.Store

OSX 10.10.1上的Python 2.7.6和Django 1.7.2。

更新

在此操作上失败的迁移脚本为pages.0007_auto_20150112_0321：

operations = [
    migrations.AlterField(
        model_name='page',
        name='store',
        field=models.ForeignKey(related_name='pages', to='stores.Store', null=True),
        preserve_default=True,
    ),

结合其他观察：

我可以在没有问题的情况下从shell创建上面的FK，但无论to设置为什么，它都能正常工作。不确定我应该在这里尝试重现错误。

如果我在迁移中将“to”字段更改为“lkjsdf”，则会给出相同类型的错误。

此外，如果我运行./manage.py migrate stores（指定应用），那么我得到：

Operations to perform:
  Apply all migrations: stores
Running migrations:
  No migrations to apply.
The following content types are stale and need to be deleted:

    products | store

Any objects related to these content types by a foreign key will also
be deleted. Are you sure you want to delete these content types?
If you're unsure, answer 'no'.

    Type 'yes' to continue, or 'no' to cancel:

所以它想删除我对stores的所有引用，这听起来不太好。

很高兴提供更多信息。谢谢！

Answer 1

在失败的迁移中有类似的问题检查依赖性

例如：

manager.requestSerializer = [AFHTTPRequestSerializer serializer];
manager.responseSerializer = [AFHTTPResponseSerializer serializer];  //AFHTTPResponseSerializer serializer
manager.responseSerializer.acceptableContentTypes = [manager.responseSerializer.acceptableContentTypes setByAddingObject:@"text/html"];

尝试将商店依赖项添加到迁移并尝试。

在Django 1.7.2中将模型迁移到新应用程序时，FK上的ValueError失败

1 个答案: