我如何解决在heroku上托管的Django项目中的迁移问题？

Question

我的项目托管在Heroku最近我想换一列的大小以dB为单位，但运行makemigrations命令后，然后再迁移命令时，它给出了一个错误，我不想失去我的数据。

   H:\shuboy2014>heroku run python manage.py makemigrations posts
   Running python manage.py makemigrations posts on shuboy2014... up, run.9067
   Migrations for 'posts':
     0003_auto_20160608_1404.py:
       - Alter field slug on post       

   H:\shuboy2014>heroku run python manage.py migrate
   Running python manage.py migrate on shuboy2014... up, run.3731
   Operations to perform:
     Apply all migrations: admin, contenttypes, posts, sessions, auth
   Running migrations:
     No migrations to apply.
     Your models have changes that are not yet reflected in a migration, and so won't be applied.
     Run 'manage.py makemigrations' to make new migrations, and then re-run 'manage.py migrate' to apply them.

任何有用的建议将是可理解的。

Answer 1

heroku run命令在具有短暂文件系统的一次性Dynos上运行，因此您正在立即销毁的文件系统上生成迁移文件。

您应该在本地生成迁移，提交并推送它们，然后执行heroku run python manage.py migrate命令。

Answer 2

我只是再次运行makemigrations和我的本地计算机上的迁移命令，然后将其推在Heroku和运行命令和它的完成。

 H:\shuboy2014>heroku run python manage.py migrate
 Running python manage.py migrate on shuboy2014... up, run.6192
 Operations to perform:
   Apply all migrations: contenttypes, auth, posts, sessions, admin
 Running migrations:
   Rendering model states... DONE
   Applying posts.0003_auto_20160608_2001... OK