如何設置的獨特屬性模型中的行

Question

我有這樣

class Competitor < ActiveRecord::Base 
    belongs_to :admin_user 
    has_many :companies 
    attr_accessible :admin_user_id, :c1, :c2, :c3, :c4, :c5 
    validates :admin_user_id, :presence => true 
    validates_uniqueness_of :admin_user_id, :message => "This user has yet a competitors list" 

end 

C1，C2模型的競爭對手，..是公司的ID。從下拉列表中選擇。我如何驗證行的唯一性？ （即管理員用戶不可能有兩個或更多等於公司，但他們可以是空的）。

Answer 1

你可以編寫自己的驗證方法來執行此操作。

class Competitor < ActiveRecord::Base 
    belongs_to :admin_user 
    has_many :companies 
    attr_accessible :admin_user_id, :c1, :c2, :c3, :c4, :c5 
    validates :admin_user_id, :presence => true 
    validates_uniqueness_of :admin_user_id, :message => "This user has yet a competitors list" 

    validate :check_companies 

    def check_companies 
    #[do your checks] 
    end 

end