diff --git a/db/migrate/20150602021020_add_score_to_work.rb b/db/migrate/20150602021020_add_score_to_work.rb
new file mode 100644
index 000000000..93045793c
--- /dev/null
+++ b/db/migrate/20150602021020_add_score_to_work.rb
@@ -0,0 +1,58 @@
+class AddScoreToWork < ActiveRecord::Migration
+  require 'bigdecimal'
+
+  def up
+    transaction do
+      for i in 1 ... 1000 do i
+        StudentWork.page(i).per(10).each do |work|
+          teacher_score = work.student_works_scores.where(:reviewer_role => 1).order("created_at desc")
+          unless teacher_score.empty?
+            work.teacher_score = teacher_score.first.score
+          end
+
+          teaching_asistant_score = work.student_works_scores.where(:reviewer_role => 2)
+          unless teaching_asistant_score.empty?
+            work.teaching_asistant_score = teaching_asistant_score.average(:score).try(:round, 2).to_f
+          end
+
+          student_socre = work.student_works_scores.where(:reviewer_role => 3)
+          unless student_socre.empty?
+            work.student_score = student_socre.average(:score).try(:round, 2).to_f
+          end
+
+          if work.teacher_score.nil?
+            if work.teaching_asistant_score.nil? #教辅评分为空，最终评分为学生匿评
+              work.final_score = work.student_score
+            elsif work.student_score.nil? #学生匿评评分为空，最终评分为教辅评分
+              work.final_score = work.teaching_asistant_score
+            else #都不为空，按比例来
+              final_ta_score = BigDecimal.new("#{work.teaching_asistant_score}") * BigDecimal.new("0.6")
+              final_s_score = BigDecimal.new("#{work.student_score}") * BigDecimal.new('0.4')
+              final_score = final_ta_score + final_s_score
+              work.final_score = format("%.2f",final_score.to_f)
+            end
+          else #教师评分不为空，最终评分为教师评分
+            work.final_score = work.teacher_score
+          end
+          work.save
+        end
+      end
+    end
+
+
+  end
+
+  def down
+    transaction do
+      for i in 1 ... 1000 do i
+        StudentWork.page(i).per(10).each do |work|
+          work.teacher_score = nil
+          work.teaching_asistant_score = nil
+          work.student_score = nil
+          work.final_score = nil
+          work.save
+        end
+      end
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index a55201b4b..6f174868e 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20150601032112) do
+ActiveRecord::Schema.define(:version => 20150602021020) do
 
   create_table "activities", :force => true do |t|
     t.integer "act_id",   :null => false