ActiveRecord::Connections provides a new way to manage multi-tenant applications based on multiples databases.

Install the activerecord-connections gem:

gem install activerecord-connections

Add this line to Gemfile:

gem 'activerecord-connections'

Runs a bundle install:

bundle install

ActiveRecord::Connections add this syntax to ActiveRecord::Base:

ActiveRecord::Base.using_connection(connection_name, connection_spec) do
  # Use database connection inside this block
end

If you are using Rails, you could use this way:

class ApplicationController < ActionController::Base
  around_filter :handle_customer

  protected

  def handle_customer(&block)
    customer = Customer.find_by_domain!(request.domain)
    customer.using_connection(&block)
  end
end

class Customer < ActiveRecord::Base
  serialize :connection_spec

  def using_connection(&block)
    ActiveRecord::Base.using_connection(id, connection_spec, &block)
  end
end

• Do not manage activerecord migrations for different databases
• Similar objects of different connections do not differ
• Coverage is not the best of the world (you could help easily)
• You will lose the connection if you call using_connection nested

Need sharding or replication? Check out one of these bad boys:

• ar-octopus
• db-charmer
• data-fabric

Copyright (c) 2011-2015 Gabriel Sobrinho, released under the MIT license.