按升序导轨排序 [英] Sort in Ascending Order Rails

问题描述

我有这个模型

模型项

class Inventory::Item < ActiveRecord::Base
  has_many :types, :class_name => "ItemType"
  attr_accessible :name
end

模型item_type

Model item_type

class Inventory::ItemType < ActiveRecord::Base
  belongs_to :item 
  attr_accessible :number
end

然后在控制器中说，我要基于项目名称以升序对类型(具有类ItemType的类型)进行排序.我该怎么办?

then let say in controller I want to sort types (which has class ItemType) in ascending order based on Item name. How do I do that?

例如，

• ItemType号= 1，项名称=表
• ItemType号= 2，项目名称= Chair
• ItemType号= 3，项目名称=窗口
• ItemType号= 4，项目名称=计算机

For example,

• ItemType number = 1 has Item name = Table
• ItemType number = 2 has Item name = Chair
• ItemType number = 3 has Item name = Window
• ItemType number = 4 has Item name = Computer

因此，我希望它不是基于数字排序，而是希望基于item.name(ASC)进行排序，如下所示:

• ItemType号= 2，项目名称= Chair
• ItemType号= 4，项目名称=计算机
• ItemType号= 1，项名称=表
• ItemType号= 3，项目名称=窗口

So instead of sorting it from number, I want it sorted based on item.name(ASC) like this:

• ItemType number = 2 has Item name = Chair
• ItemType number = 4 has Item name = Computer
• ItemType number = 1 has Item name = Table
• ItemType number = 3 has Item name = Window

推荐答案

这种方法应该可以解决问题...

Something like this should do the trick...

ItemType.includes( :item ).order( 'inventory_items.name DESC' )

此外，如果您需要在许多位置执行此操作，则可以通过为has_many调用提供:order参数来完成同一件事，而不是-

Also, if you need to do this in many locations, you can accomplish the same thing by providing an :order parameter to your has_many call, instead - http://apidock.com/rails/ActiveRecord/Associations/ClassMethods/has_many.

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