Rails 3 - ActiveRecord和反向排序

Question

I have following data in database:

1
2
3
4
5

And I would like to get to output this:

3
4
5

I need it to print in the view:

<%car.colors.limit(3).order('created_at ASC').each do |color|%>
  ...

I know that exists reverse_order , but exist something like reverse sort ?

(I know that is possible to load the data into an array and then go through the array, but this way is not very efficient)

Answer 1

刚做的怎么样

<%car.colors.limit(3).order('created_at DESC').reverse.each do |color|%>

Answer 2

For Rails 4:

[Model].order(column: :desc)

For Rails 3:

[Model].order("<column> DESC")

For Rails 2:

[Model].all(:order => "<column> DESC")

Answer 3

One line Solution

in your controller use:

class Api::ImagesController < ApplicationController

  def index
    @posts =  Post.all.paginate(:page => params[:page], :per_page => 4).order(id: :desc)
    render :json => @posts.to_json(:methods => [:image_url])
  end

end