class Item
include DataMapper::Resource
property :id, Serial
property :title, String
end
item = Item.new(:title => 'Title 1') # :id => 1
item.save
item_clone = Item.first(:id => 1).clone
item_clone.save
# => <Item @id=1 @title="Title 1" ...
这确实会像描述的那样“克隆”对象,但是如何在记录保存后应用不同的ID呢?
# => <Item @id=2 @title="Title 1" ...