Ruby on rails 嵌套集是否可以有重复的子对象或多个父\u id/根/节点？

嵌套集是否可以有重复的子对象或多个父\u id/根/节点

例如，我想创建一个可以管理零件和设备的应用程序。但是，特定设备也可以具有与其他设备相同的部件

你有什么想法吗

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谢谢你

我认为这里需要的是一个关联类来帮助建模多对多关系。在rails中，这可能类似于：

class Equipment < ActiveRecord::Base
  has_many :part_relationships
  has_many :parts, :through => :part_relationships
end

class Part < ActiveRecord::Base
  has_many :part_relationships
  has_many :equipment, :through => :part_relationships
end

class PartRelationship < ActiveRecord::Base
  belongs_to :equipment
  belongs_to :part
end

e = Equipment.find(:first)
e.parts # Returns all the parts on this equipment, including shared

p = Part.find(:first)
p.equipment # Returns all equipment this part features in.

# Create a new relationship between e and p
PartRelationship.create(:equipment => e, :part => p)