迁移问题

db/migrate/20200223021427_sync_subjectds_mobile.rb

@@ -1,7 +1,7 @@
 class SyncSubjectdsMobile < ActiveRecord::Migration[5.2]
   def change
     SubDisciplineContainer.find_each do |sc|
-      subject.find(sc.container_id).update_column(:show_mobile => true)
+      Subject.find(sc.container_id).update_column(:show_mobile, true)
     end
   end
 end