gistfile1.txt

class TravelOption < ApplicationRecord
  has_many :travels
end


class Travel < ApplicationRecord
  belongs_to :travel_option
end

>> TravelOption.joins(:travels).where(location_id: 1).select(:location_id, :price, :tour_id).map(&:tour_id)
  TravelOption Load (2.5ms)  SELECT "travel_options"."location_id", "travel_options"."price", "tour_id" FROM "travel_options" INNER JOIN "travels" ON "travels"."travel_option_id" = "travel_options"."id" WHERE "travel_options"."location_id" = $1  [["location_id", 1]]
=> [1, 2, 3, 4]