活动记录按最小值排序

Question

I have a few models, City, Hotel, and Room. City has_many hotels, hotels has_many rooms. Each room has a price. I'm trying to sort by the lowest price room, asc and desc.

In my results, I'm also showing the lowest price for a hotel. I'm able to successfully sort by price ass with this

City.first.includes(hotel: :rooms).order("rooms.price asc")

But since I want to always show the lowest price, this doesn't work if I want to sort high to low since it sorts by the highest room price for a hotel.

Is there a way to sort by a hotels minimum room price? If I try to order by MIN(rooms.price) desc I get an error.

Answer 1

City model

attr_accessible :name
has_many :hotels

Hotel model

attr_accessible :city_id, :name
has_many :rooms
belongs_to :city

City model

attr_accessible :hotel_id, :name, :price
belongs_to :hotel

Please have a try with

@rooms = Room.includes([:hotel => [:city]]).select('hotel_id, MIN(price) AS price').group('hotel_id').order('MIN(rooms.price) ASC')

In your view file

<% @rooms.each do |room| %>
 <div>
   <div><%= room.hotel.name</div>
   <div><%= room.hotel.city%></div>
   <div><%= room.price%></div>
 </div>
<% end %>