You can call establish_connection with the key that points to another database config in your config/database.yml
class Person < ActiveRecord::Base
establish_connection(:hr)
end
class Ticket < ActiveRecord::Base
establish_connection(:bug_tracker)
end
If you have a whole bunch of models that need to connect to another database:
class HR < ActiveRecord::Base
establish_connection(:hr)
end
class People < HR
# ...
end
class Resource < HR
# ...
end