我正在尝试实现如下结构:GrandFather <- Father <- Son Using rails 和 gem citier。这个例子应该创建 2 个表来表示 3 个类:一个用于 Root 类(GrandFather)及其属性,另一个用于表示父类和子类(因为 Son 没有额外的属性)和父类的属性。
class GrandFather < ActiveRecord::Base
acts_as_citier
attr_accessible :grand_father_attr, :type
end
class Father < GrandFather
acts_as_citier
attr_accessible :father_attr
end
class Son < Father
end
class CreateGrandFathers < ActiveRecord::Migration
def change
create_table :grand_fathers do |t|
t.string :type
t.string :grand_father_attr
t.timestamps
end
end
end
class CreateFathers < ActiveRecord::Migration
def up
create_table :fathers do |t|
t.string :father_attr
end
create_citier_view(Father)
end
def down
drop_citier_view(Father)
drop_table :fathers
end
end
但是,如果我打开 rails 控制台并键入“Son.new”,则来自 GrandFather 的属性就在那里,但缺少来自父亲类的属性:
1.9.3-p362 :001 > Son.new
citier -> Root Class
citier -> table_name -> grand_fathers
citier -> Non Root Class
citier -> table_name -> fathers
citier -> tablename (view) -> view_fathers
(1.1ms) SELECT COUNT(*)
FROM pg_tables
WHERE tablename = 'grand_fathers'
(0.5ms) SELECT COUNT(*)
FROM pg_views
WHERE viewname = 'grand_fathers'
=> #<Son id: nil, type: "Son", grand_father_attr: nil, created_at: nil, updated_at: nil>