Molo (We're riding solo!)
Molo provides Rails database migrations for non-Rails and non-Ruby projects. By dropping a Rakefile into your projects root, Molo will provide you with a list of Rake tasks for managing your database schema and data.
The following tasks are provided:
rake db:data:dump # Dump contents of database to db/data.extension (defaults to yaml; ignore tables with 'except' or ignore all those woth 'only')
rake db:data:dump_dir # Dump contents of database to db/data/tablename.extension (defaults to yaml; ignore tables with 'except' or ignore all those woth 'only')
rake db:data:load # Load contents of db/data.extension (defaults to yaml) into database
rake db:data:load_dir # Load contents of db/data/* into database
rake db:dump # Dump schema and data to db/schema.rb and db/data.yml
rake db:load # Load schema and data from db/schema.rb and db/data.yml
rake db:migrate # Migrate the database using the scripts in the migrations directory.
rake db:migrate:down # Runs the "down" for a given migration VERSION.
rake db:migrate:redo # Rollbacks the database one migration and re migrate up (options: STEP=x, VERSION=x).
rake db:migrate:status # Display status of migrations
rake db:migrate:up # Runs the "up" for a given migration VERSION.
rake db:new_migration # Create a new migration
rake db:rollback # Rolls the schema back to the previous version (specify steps w/ STEP=n).
rake db:schema:dump # Create schema.rb file that can be portably used against any DB supported by AR
rake db:schema:load # Load a ar_schema.rb file into the database
rake db:test:load # Recreate the test database from the current schema.rb
rake db:test:prepare # Check for pending migrations and load the test schema
rake db:test:purge # Empty the test database
rake db:version # Retrieves the current schema version number
Installation
Install Ruby, RubyGems and a ruby-database driver (e.g. gem install mysql2) then:
sudo gem install molo
Add to Rakefile in your projects base directory:
begin
require 'tasks/molo'
MigratorTasks.new do |t|
# t.migrations = "db/migrations"
# t.config = "db/config.yml"
# t.schema = "db/schema.rb"
# t.env = "DB"
# t.default_env = "development"
# t.verbose = true
# t.log_level = Logger::ERROR
end
rescue LoadError => e
puts "Run 'gem install molo' to get db:migrate:* tasks! (Error: #{e})"
end
Create a db directory at your project root and add database configuration to db/config.yml. Here's an example DB config.
development:
adapter: sqlite3
database: db/development.sqlite3
pool: 5
timeout: 5000
production:
adapter: mysql
encoding: utf8
reconnect: false
database: somedatabase_dev
pool: 5
username: root
password:
socket: /var/run/mysqld/mysqld.sock
test:
adapter: sqlite3
database: db/test.sqlite3
pool: 5
timeout: 5000
To create a new database migration:
rake db:new_migration name=FooBarMigration
edit db/migrations/20081220234130_foo_bar_migration.rb
... and fill in the up and down migrations Cheatsheet.
If you're lazy and want to just execute raw SQL:
def self.up
execute "insert into foo values (123,'something');"
end
def self.down
execute "delete from foo where field='something';"
end
To apply your newest migration:
rake db:migrate
To migrate to a specific version (for example to rollback)
rake db:migrate VERSION=20081220234130
To migrate a specific database (for example your "testing" database)
rake db:migrate DB=test
To execute a specific up/down of one single migration
rake db:migrate:up VERSION=20081220234130
Contributors
This work is based on Lincoln Stoll's blog post and David Welton's post.