def exact_column(*names)

      exact_column_names = exact_column_names||[]
      exact_column_names += names

      names.each do |name|
        name = name.to_s
        instance_eval do
          scope :"#{name}_is", ->(value) { where "#{name}_exact_signature" => exact_signature(self, name, value) }
          before_save do send "#{name}_exact_signature=", self.class.exact_signature(self.class, name, send(name)) end
        end
      end

    end
def exact_column(*names)

      exact_column_names = exact_column_names||[]
      exact_column_names += names

      names.each do |name|
        name = name.to_s
        instance_eval do
          scope :"#{name}_is", ->(value) { where "#{name}_exact_signature" => exact_signature(self, name, value) }
          before_save do send "#{name}_exact_signature=", self.class.exact_signature(self.class, name, send(name)) end
        end
      end

    end
配置精确索引列。如：
 class SomeModel
   include Unidom::Common::Concerns::ExactColumn
   exact_column :phone_number, :identification_number
 end