What if we mistakenly deleted some migration file..?

Question

I have deleted some migration file mistakenly. Those files are already migrated. If I am creating migration with same name, and fire rake db:migrate command it is showing me message that Table already exist. Is there any way to regain those files?

please help..

Answer 1

You will find information about previous migration in config/schema.rb

There is no need of keeping old migration files if all databases (developers, staging and production) have been migrated. Even if you did not delete the old files, they would not prevent you from getting a error message if you try to create a duplicate table.

Answer 2

I am relatively new to RoR. However, I'm a bit concerned that losing this file will present some problems if you aspire to host your app on a server other than the one it is currently hosted on. For example, if you had a mind to host the app in Heroku, you would need to run your migrations in that environment.

If you are not terribly far along with your application, it would be best to start over, take care not to delete your migrations, and put your app under version control so that you will have a fallback should you run into this problem in the future.