How to perform such join tables in ActiveRecord?

Question

I need help in doing the following join using ActiveRecord relation models:

select "access_urls"."id", "controller_urls"."controller", "action_urls"."action" from
"access_urls"
inner join "controller_urls"
on "controller_urls"."id" = "access_urls"."controller_url_id"
inner join "action_urls"
on "action_urls"."id" = "access_urls"."action_url_id"

Where I have AccessUrl, ActionUrl and ControllerUrl models

class AccessUrl < ActiveRecord::Base
  belongs_to :controller_url
  belongs_to :action_url
end

class ActionUrl < ActiveRecord::Base
  has_many :access_urls
  validates :action, presence: true, uniqueness: { message: "já encontra-se em uso." }
end

class ControllerUrl < ActiveRecord::Base
  has_many :access_urls
  validates :controller, presence: true, uniqueness: { message: "já encontra-se em uso." }
end

Can anyone help me?

Answer 1

Using joins:

result = AccessUrl.joins(
  :controller_url, :action_url
).select(
  'access_urls.id, controller_urls.control, action_urls.action'
)

This will give you a relation result containing objects of AccessUrl. You can loop through the result and access the selected columns as:

result.each do |r| 
  # r.id
  # r.control
  # r.action
end