如何在Rails中保留关联记录的顺序？

Question

I am trying to work out an interface that allows user to rearrange the records on the page and make sure that when they save the order is preserved. I approached it first by creating a field for order

class Node
  field :order, :type=>Integer
end

node_ids = ["42dw23ffe3", "56dfsa2edfsd"]

But I run into a wall trying to make is work in an efficient way. The method I think of requires making twice as many queries as there are nodes -- looking up and updating.

Is there a better way of keeping a set of nodes in an arbitrary, user-specified order?

Answer 1

观看此http://railscasts.com/episodes/147-sortable-lists