> rails c

Attachment.all.each do |att|
  att.image.recreate_versions!
  att.save!
end

$ rake db:create          # Create the database from DATABASE_URL or config/database.yml for the current Rails.env (use db:create:all to create all dbs in the config)
$ rake db:drop            # Drops the database using DATABASE_URL or the current Rails.env (use db:drop:all to drop all databases)
$ rake db:fixtures:load   # Load fixtures into the current environment's database
$ rake db:migrate         # Migrate the database (options: VERSION=x, VERBOSE=false)
$ rake db:migrate:status  # Display status of migrations
$ rake db:rollback        # Rolls the schema back to the previous version (specify steps w/ STEP=n)
$ 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:seed            # Load the seed data from db/seeds.rb
$ rake db:setup           # Create the database, load the schema, and initialize with the seed data (use db:reset to also drop the db first)
$ rake db:structure:dump  # Dump the database structure to db/structure.sql
$ rake db:version         # Retrieves the current schema version number