使用委托属性Rails validates_uniqueness_of

Question

尝试范围：名称为View的父级：表单

上的属性

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

为什么不在表单上查找facility_id？

而是在View

上查找它

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

Answer 1

我相信这段时间以前曾经有过工作，很有可能它仍然有效：

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