课程配置删除唯一的课程体系不成功

app/controllers/admins/subject_settings_controller.rb

@@ -8,8 +8,8 @@ class Admins::SubjectSettingsController < Admins::BaseController
   end
 
   def update
-    if params[:sub_disciplines]
+    sub_discipline_ids = params[:sub_disciplines] || []
-      sub_ids = params[:sub_disciplines].reject(&:blank?).map(&:to_i)
+    sub_ids = sub_discipline_ids.reject(&:blank?).map(&:to_i)
     old_sub_ids = current_subject.sub_discipline_containers.pluck(:sub_discipline_id)
     new_ids = sub_ids - old_sub_ids
     delete_ids = old_sub_ids - sub_ids
@@ -19,7 +19,6 @@ class Admins::SubjectSettingsController < Admins::BaseController
       current_subject.sub_discipline_containers.create!(sub_params)
     end
   end
-  end
 
   private