我有两张桌子:
货币和利率
currencies: id:int, code:string, name: string
rates: id:int, top_currency_id:int, bottom_currency_id:int, rate:float
我有两个活跃的记录:
class Rate < ActiveRecord::Base
attr_accessible :bottom_currency, :rate, :top_currency, :top_currency_id
belongs_to :top_currency, :class_name => 'Currency', :foreign_key => 'top_currency_id'
belongs_to :bottom_currency, :class_name => 'Currency', :foreign_key => 'bottom_currency_id'
end
class Currency < ActiveRecord::Base
attr_accessible :code, :name
has_many :rates
end
所以问题是:当我要执行以下代码时:top_currency = Currency.find_by_id(1)@test = Rate.where(:top_currency => top_currency)
我收到以下错误:
Mysql2::Error: Unknown column 'rates.top_currency' in
'where clause': SELECT `rates`.* FROM `rates` WHERE `rates`.`top_currency` = 1
为什么Rails的魔法不起作用？
非常感谢.