Django-South DataMigration - 应用程序可用于转发（）但不能倒退（）？

Question

I am writing a django south migration that depends on the model in another app, so I have included --freeze OTHERAPPNAME when I ran python manage.py datamigration … 我正在编写一个django南迁移，它取决于另一个应用程序中的模型，所以我在运行python manage.py datamigration … --freeze OTHERAPPNAME时包含了--freeze OTHERAPPNAME python manage.py datamigration …

However in the forwards() function I can access the other model fine (with orm['otherappname.MyModelName'] ), however in the backwards() step (which also depends on the model in otherappname), if I try to access orm['otherappname.MyModelName'] , I get an error 但是在forwards()函数中我可以访问其他模型（使用orm['otherappname.MyModelName'] ），但是在backwards()步骤中（这也取决于其他名称中的模型），如果我尝试访问orm['otherappname.MyModelName'] ，我收到一个错误

*** KeyError: "The model 'mymodelname' from the app 'otherappname' is not available in this migration."

I can see the frozen model details in the bottom of the file. 我可以在文件底部看到冻结的模型细节。 Why can't I access it? 为什么我不能访问它？

NB: This model is created in another migration inside otherappname of which this datamigration depends on. 注意：此模型是在此数据迁移所依赖的其他迁移内创建的。

Answer 1

The backwards migration actually uses the frozen ORM of the previous migration. 向后迁移实际上使用先前迁移的冻结ORM。 It's logical when you think about it, but it's admittedly not very intuitive. 你考虑它是合乎逻辑的，但它确实不是很直观。

Moral: freeze the models you'll need in your datamigration in the schemamigration that proceeds it. 道德：冻结您在进行数据迁移的模式迁移中需要的模型。

Django-South DataMigration - 应用程序可用于转发（）但不能倒退（）？

问题描述

1 个解决方案

解决方案1
10 已采纳 2012-03-02 17:30:22

Django-South DataMigration - 应用程序可用于转发（）但不能倒退（）？

问题描述

1 个解决方案

解决方案1 10 已采纳 2012-03-02 17:30:22

解决方案1
10 已采纳 2012-03-02 17:30:22