迁移空数据问题

db/migrate/20160405021915_delete_anonymous_work.rb

@@ -1,5 +1,6 @@
 class DeleteAnonymousWork < ActiveRecord::Migration
   def up
+    begin
       student_works = StudentWork.where("homework_common_id = 2882").map{|work| work.id} unless StudentWork.where("homework_common_id = 2882").empty?
       student_work_ids = "(" + student_works.join(",") + ")"
       student_work_scores = StudentWorksScore.where("student_work_id in #{student_work_ids}")
@@ -12,6 +13,9 @@ class DeleteAnonymousWork < ActiveRecord::Migration
           student_work.save
         end
       end
+    rescue => e
+      logger.error "[Errno::ENOENT] ===> #{e}"
+    end
   end
 
   def down