How to revert all migrations at once in Ruby on Rails 3?

Question

I tried to run:

rake db:migrate VERSION=0

It reverts all migrations except the last one.

Then I tried to run:

rake db:migrate:down VERSION=<timestamp_of_last_migration>

but it didn't revert either. Why ?

Is there a command that runs all down methods at once ?

Answer 1

If your database only related to this project, and you are trying to undo everything in your migrations, I'd simply drop the database, and then run rake db:create.

Then you have an empty database ready to go.

Or is there another reason you're trying to run the down scripts?

Answer 2

You could check this list.

Maybe this could help you

rake db:create[:all]: If :all not specified then create the database defined in config/database.yml for the current RAILS_ENV. If :all is specified then create all of the databases defined in config/database.yml.
rake db:fixtures:load: Load fixtures into the current environment's database. Load specific fixtures using FIXTURES=x,y
rake db:migrate [VERSION=n]: Migrate the database through scripts in db/migrate. Target specific version with VERSION=n
rake db:migrate:redo [STEP=n]: (2.0.2) Revert the database by rolling back "STEP" number of VERSIONS and re-applying migrations.
rake db:migrate:reset: (2.0.2) Drop the database, create it and then re-apply all migrations. The considerations outlined in the note to rake db:create apply.
rake db:reset: Drop and re-create database using db/schema.rb. The considerations outlined in the note to rake db:create apply.
rake db:rollback [STEP=N]: (2.0.2) Revert migration 1 or n STEPs back.
rake db:schema:dump: Create a db/schema.rb file that can be portably used against any DB supported by AR
rake db:schema:load: Load a schema.rb file into the database
rake db:sessions:clear: Clear the sessions table
rake db:sessions:create: Creates a sessions table for use with CGI::Session::ActiveRecordStore
rake db:structure:dump: Dump the database structure to a SQL file
rake db:test:clone: Recreate the test database from the current environment's database schema
rake db:test:clone_structure: Recreate the test databases from the development structure
rake db:test:prepare: Prepare the test database and load the schema
rake db:test:purge: Empty the test database

Answer 3

there is another way:

rake db:rollback STEP=100

this will revert last 100 migrations

taken from http://guides.rubyonrails.org/migrations.html#rolling-back

Answer 4

try:

rake db:migrate:down VERSION=<timestamp_of_first_migration>

this will run the self.down for your first migration, essentially wiping everything out. at least, it just did for me!