Rails migrations in non-Rails (and non Ruby) projects.
In the 2.x release we have moved to using Rails 3 migrations instead of maintaining our own migration related code. Just about anything you can do with Rails 3 migrations you can now do with Standalone Migrations too! This removed 95% of the code we have to maintain. Big thanks to Ricardo Valeriano and Michael Grosser for undertaking this major rewrite!
Standalone Migrations relies on the contributions of the open-source community! To submit a fix or an enhancement fork the repository, checkout the develop branch, make your changes, add your name to the Contributors section in README.markdown, and send us a pull request! If you're active and do good work we'll add you as a collaborator!
Install Ruby, RubyGems and a ruby-database driver (e.g. gem install mysql
) then:
gem install standalone_migrations
Add to Rakefile
in your projects base directory:
require 'standalone_migrations'
StandaloneMigrations::Tasks.load_tasks
Add database configuration to db/config.yml
in your projects base directory e.g.:
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: &test
adapter: sqlite3
database: db/test.sqlite3
pool: 5
timeout: 5000
rake db:new_migration name=foo_bar_migration
edit db/migrate/20081220234130_foo_bar_migration.rb
def up
execute "insert into foo values (123,'something');"
end
def down
execute "delete from foo where field='something';"
end
rake db:migrate
rake db:migrate VERSION=20081220234130
rake db:migrate DB=test ... or ...
rake db:migrate RAILS_ENV=test
rake db:migrate:up VERSION=20081220234130
rake db:rollback
rake db:rollback STEP=3
By default, Standalone Migrations will assume there exists a "db/" directory in your project. But if for some reason you need a specific directory structure to work with, you can use a configuration file named .standalone_migrations in the root of your project containing the following:
db:
seeds: db/seeds.rb
migrate: db/migrate
schema: db/schema.rb
config:
database: db/config.yml
These are the configurable options available. You can omit any of the keys and Standalone Migrations will assume the default values.
If you are using Heroku or have to create or change your connection
configuration based on runtime aspects (maybe environment variables),
you can use the StandaloneMigrations::Configurator.environments_config
method. Check the usage example:
require 'tasks/standalone_migrations'
StandaloneMigrations::Configurator.environments_config do |env|
env.on "production" do
if (ENV['DATABASE_URL'])
db = URI.parse(ENV['DATABASE_URL'])
return {
:adapter => db.scheme == 'postgres' ? 'postgresql' : db.scheme,
:host => db.host,
:username => db.user,
:password => db.password,
:database => db.path[1..-1],
:encoding => 'utf8'
}
end
nil
end
end
You have to put this anywhere on your Rakefile
. If you want to
change some configuration, call the #on method on the object
received as argument in your block passed to ::environments_config
method call. The #on method receives the key to the configuration
that you want to change within the block. The block should return
your new configuration hash or nil if you want the configuration
to stay the same.
Your logic to decide the new configuration need to access some data in your current configuration? Then you should receive the configuration in your block, like this:
require 'tasks/standalone_migrations'
StandaloneMigrations::Configurator.environments_config do |env|
env.on "my_custom_config" do |current_custom_config|
p current_custom_config
# => the values on your current "my_custom_config" environment
nil
end
end
If instead of the database-agnostic schema.rb
file you'd like to
save the database-specific SQL generated by the migrations, simply
add this to your Rakefile
.
require 'tasks/standalone_migrations'
ActiveRecord::Base.schema_format = :sql
You should see a db/structure.sql
file the next time you run a
migration.
- Todd Huss
- Michael Grosser
- Ricardo Valeriano
- Two Bit Labs
- ClassMonkeys
- Windandtides
- Eric Lindvall
- Steve Hodgkiss
- Rich Meyers
- Wes Bailey
- Robert J. Berger
- Federico Builes
- Gazler
- Yuu Yamashita
- Koen Punt
This work is originally based on Lincoln Stoll's blog post and David Welton's post.