livingsocial / connectomatic

A simple gem that makes it easy to use multiple databases from Rails

connectomatic

This gem provides a simple way of managing multiple activerecord connections.

Supports Rails >= 3.2

Config structure

In addition to a rails project's primary database defined in config/database.yml, connectomatic allows you to define additional databases by placing any number of <database_name>.yml files in a config/databases/ directory. Each database config file uses the same format as a normal database.yml file.

Rake tasks

rake db:connectomatic:create_all creates all the defined databases. rake db:connectomatic:drop_all drops all the defined databases.

TODO: Schema dump and schema load for additional databases.

Using the databases

ActiveRecord Models

Just invoke the connectomatic method and pass it the name of the database you'd like it to use in your model object.

class MyModel < ActiveRecord::Base
      connectomatic(:my_database)
end

Migrations

To run a migration on an alternate database, just invoke the self.connectomatic method in your migration class and pass it the name of the database you'd like it to use.

class CreateSomething < ActiveRecord::Migration

      connectomatic(:my_database)

      def self.up
          #
      end

      def self.down
          #
      end
end

Explicitly specifying the default Rails database

Just pass :default to the connectomatic method in a Migration or a Model.

Credits

Inspiration for this gem (and several of the techniques used) were provided by Chris Herring's connection_ninja gem. (https://github.com/cherring/connection_ninja)