Rails的validate_uniqueness_of與delgate財產

Question

試圖範圍：名稱上查看的父屬性：形式

class View < ActiveRecord::Base 
    belongs_to :form 
    delegate :facility_id, to: :form 
    validates_uniqueness_of :name, scope: :facility_id 
    attr_accessible :name 

爲什麼它不尋求facility_id的形式？

相反，它會尋找它查看

ActiveRecord::StatementInvalid - PG::UndefinedColumn: ERROR: column views.facility_id does not exist 

Answer 1

我相信這個曾經工作，前一段時間，沒準它仍然有效：

validates_uniqueness_of :name, scope: { :form => :facility_id }