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alvincrespo
alvincrespo

Reputation: 9334

How to delete migration files in Rails 3

I would like to remove/delete a migration file. How would I go about doing that? I know there are similar questions on here but as an update, is there a better way than doing script/destroy?

Also, should I do a db:reset or db:drop if I remove/delete a migration?

Upvotes: 117

Views: 175895

Answers (11)

Gediminas Šukys
Gediminas Šukys

Reputation: 7391

Another way to delete the migration:

$ rails d migration SameMigrationNameAsUsedToGenerate

Use it before rake db:migrate is executed because changes in database will stay forever :) - or remove changes in Database manually

Upvotes: 87

Vicky
Vicky

Reputation: 419

You can also run a down migration like so:

rake db:migrate:down VERSION=versionnumber

Refer to the Ruby on Rails guide on migrations for more info.

Upvotes: 10

Mohamed Daw
Mohamed Daw

Reputation: 81

Side Note: Starting at rails 5.0.0 rake has been changed to rails So perform the following

rails db:migrate VERSION=0

Upvotes: 0

random_user_0891
random_user_0891

Reputation: 2051

This also works in Rails 5.

If the migration was the most recent one you can remove the database column(s) that the migration added by doing: 

rake db:rollback

then remove the migration file itself by running:

rails d migration WhateverYourMigrationWasNamed.rb

Upvotes: 4

stackPusher
stackPusher

Reputation: 6512

None of these answers quite fit the problem i had as the migration i wanted to delete was missing: I had created and run a migration in some other branch, which was then discarded. The problem is when a migration is run, rails adds the version into a schema_migrations table in the database. So even if it isn't listed in your db structure or schema, rails looks for it. You can reveal these orphaned migrations by running:

rails db:migrate:status

Note the versions of the missing migrations and head into the db console:

rails dbconsole

Now remove the versions from the migration table manually:

delete from schema_migrations where version='<version>';

You should now be good.

Upvotes: 11

fOx
fOx

Reputation: 277

Run below commands from app's home directory:

  1. rake db:migrate:down VERSION="20140311142212" (here version is the timestamp prepended by rails when migration was created. This action will revert DB changes due to this migration)

  2. Run "rails destroy migration migration_name" (migration_name is the one use chose while creating migration. Remove "timestamp_" from your migration file name to get it)

Upvotes: 26

Miguel Alatorre
Miguel Alatorre

Reputation: 1

I just had this same problem:

  1. rails d migration fuu -this deleted the migration with the last timestamp
  2. rails d migration fuu -this deleted the other migration
  3. use git status to check that is not on the untracked files anymore
  4. rails g migration fuu

That fixed it for me

Upvotes: 0

Agnes
Agnes

Reputation: 141

We can use,

$ rails d migration table_name

Which will delete the migration.

Upvotes: 10

user1781626
user1781626

Reputation:

Look at 4.1 Rolling Back

http://guides.rubyonrails.org/migrations.html

$ rake db:rollback

Upvotes: 1

frenesim
frenesim

Reputation: 703

Sometimes I found myself deleting the migration file and then deleting the corresponding entry on the table schema_migrations from the database. Not pretty but it works.

Upvotes: 3

F&#225;bio Batista
F&#225;bio Batista

Reputation: 25260

I usually:

  1. Perform a rake db:migrate VERSION=XXX on all environments, to the version before the one I want to delete.
  2. Delete the migration file manually.
  3. If there are pending migrations (i.e., the migration I removed was not the last one), I just perform a new rake db:migrate again.

If your application is already on production or staging, it's safer to just write another migration that destroys your table or columns.

Another great reference for migrations is: http://guides.rubyonrails.org/migrations.html

Upvotes: 154

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