上移下移功能

app/models/inform.rb

@@ -7,11 +7,11 @@ class Inform < ApplicationRecord
   has_many :attachments, as: :container, dependent: :destroy
 
   def next_inform
-    Inform.where(position: self.position+1, container_id: self.course_id, container_type: 'Course')
+    Inform.where(position: self.position+1, container_id: self.container_id, container_type: self.container_type)
   end
 
   def  last_inform
-    Inform.where(position: self.position-1, container_id: self.course_id, container_type: 'Course')
+    Inform.where(position: self.position-1, container_id: self.container_id, container_type: self.container_type)
   end
 
 end