Partendo dalle risposte precedenti, ma incorporando alcuni vantaggi di Rails 3 con la configurazione e semplificando l'analisi...
# config/application.rb
module MyApp
class Application < Rails::Application
... other configs
config.secondary_database_url = ENV['SECONDARY_DB_URL']
end
end
Potremmo voler ignorare questo in fase di sviluppo/test
# config/environments/development.rb
module MyApp
class Application < Rails::Application
... other configs
config.secondary_database_url = 'SOME_CONNECTION_STRING'
end
end
Ora, per impostare la classe, faremo ereditare i nostri modelli da...
# lib/active_record/secondary.rb
module ActiveRecord
class Secondary < ActiveRecord::Base
self.abstract_class = true
# prior to AR 3.2.1
url = URI.parse( MyApp::Application.config.secondary_database_url )
establish_connection(
:adapter => 'mysql',
:host => url.host,
:username => url.userinfo.split(':')[0],
:password => url.userinfo.split(':')[1],
:database => url.path[1..-1],
:port => url.port || 3306
)
# as of AR 3.2.1
establish_connection(MyApp::Application.config.secondary_database_url)
end
class SecondaryMigration < ActiveRecord::Migration
def connection
ActiveRecord::Secondary.connection
end
end
end
