Rails 3+之后支持的validate整合写法

在 Rails3 之後支援以下的整合法：

validates :name,  :presence => true,                   :length => {:minimum => 1, :maximum => 254}               validates :email, :presence => true,                   :length => {:minimum => 3, :maximum => 254},                  :uniqueness => true,                  :email => true

如果需要客化息的：

validates :name,  :presence => { :message => "不能空白" } ,                   :length => {:minimum => 1, :maximum => 254, :message => "度不正" }