gistfile1.rb

class AddProfileIdToTestimonials < ActiveRecord::Migration
    def change
      add_column :testimonials, :profile_ids, :integer, array: true

      reversible do |dir|
        dir.up do
          execute <<-SQL
            update testimonials set profile_ids = (select array_agg(profiles.id) from profiles
              where profiles.accounts_id = testimonials.account_id;)
          SQL
        end
      end
    end
end
end