Rails Migrations Cheatsheet

Up and down methods, rake tasks, column mapping, loading fixtures, example migration file, all packed onto one A4 page for an easy at-a-glance reference. Updated for Rails 2.1

db:create db:create:all	Creates a single database specified in config/databases.yml for the current RAILS_ENV or creates all the databases
db:drop db:drop:all	Drops a single database specified in config/databases.yml for the current RAILS_ENV or drops all the databases
db:fixtures:load	Load fixtures from test/fixtures into the current environment's database
db:migrate	Run all unapplied migrations
db:migrate:up db:migrate:down	Move forward to the next migration, or back to the previous migration
db:migrate VERSION=18	Migrate database to specific version
db:migrate RAILS_ENV=production	Use migrations to recreate tables in the testing or production databases
db:schema:dump	Create a db/schema.rb file that can be portably used against any database supported by ActiveRecord
db:schema:load	Load a schema.rb file into the database
db:sessions:create	Create a sessions table for use with CGI::Sessions::ActiveRecordStore
db:sessions:clear	Clear the sessions table
db:structure:dump	Dump database structure to SQL file
db:reset	Drops the database, creates the database and then runs migrations against the database. Takes a VERSION argument as well as RAILS_ENV
db:rollback STEP=4	Takes a STEP argument to determine how many version to rollback, the default being one version
db:test:prepare	Clone your database structure into the test database
db:version	Tells you the current version your database is at

A look at the new features and syntax available in migrations on Rails 2.0 More

A brilliant plugin that makes changing your database schema even easier and faster. More