Question

class Channel < ActiveRecord::Base
  has_many :programs

end

class Program < ActiveRecord::Base
  belongs_to :channel
  has_many :program_schedules

end

class ProgramSchedule < ActiveRecord::Base
  belongs_to :program
end

I would want to get an array of data like this:

• Channel 1:

  • Program 1

    • Schedule 1

  • Program 2

    • Schedule 1
    • Schedule 2
    • Schedule 3

• Channel 2:

  • Program 1
    • Schedule 1
    • Schedule 2
    • Schedule 3

I have tried with this query, but it retrieve only “channel”-rows (without Programs and Schedules)

 @data = Channel.joins(:programs => :program_schedules).group("channel_id")

Answer 1

I would not recommend you to get all rows this way.

Do something like this.

In your controller, say in index action

def index
  @channels = Channel.all
end

In the view where you want to show everything.

%ul#channels
  = @channels.each do |channel|
    %li= channel.name
    %ul.channel
      = channel.programs.each do |program|
        %li= program.name
        %ul.program
          = program.schedules.each do |schedule|
            %li= schedule.name