rails命名空间模型 - 关联

Question

当我尝试使用has_many：through关联时，它似乎在连接表中查找通用键。实施例

class Ots::Foo < ActiveRecord::Base
  has_many :foo_bars, :class_name => '::Ots::FooBar', :foreign_key => :ots_foo_id
  has_many :bars, :class_name => '::Ots::Bar', :through => :foo_bars
end

class Ots::Bar < ActiveRecord::Base
  has_many :foo_bars, :class_name => '::Ots::FooBar', :foreign_key => :ots_bar_id
  has_many :bars, :class_name => '::Ots::Bar', :through => :foo_bars
end

class Ots::FooBar < ActiveRecord::Base
  belongs_to :foo, :class_name => "::Ots::Foo", :foreign_key => :ots_foo_id
  belongs_to :bar, :class_name => "::Ots::Bar", :foreign_key => :ots_bar_id
end

f = Foo.find(1)
f.bars  =># invalid column name 'bar_id'

这是我应该期待的吗？命名空间是否有更优雅的解决方案？