增加手动评分相关表，以及关系的定义

app/models/homework_common.rb

@@ -1,7 +1,9 @@
 #老师布置的作业表
+#homework_type: 1:普通作业;2:匿评作业;3:编程作业
 class HomeworkCommon < ActiveRecord::Base
   attr_accessible :name, :user_id, :description, :publish_time, :end_time, :homework_type, :late_penalty, :course_id
 
   belongs_to :course
   belongs_to :user
+  has_many :homework_detail_manuals, :dependent => :destroy
 end

app/models/homework_detail_manual.rb

@@ -0,0 +1,5 @@
+class HomeworkDetailManual < ActiveRecord::Base
+   attr_accessible :ta_proportion, :comment_status, :evaluation_start, :evaluation_end, :evaluation_num, :absence_penalty, :homework_common_id
+
+  belongs_to :homework_common
+end

db/migrate/20150519014600_create_homework_detail_manuals.rb

@@ -0,0 +1,15 @@
+class CreateHomeworkDetailManuals < ActiveRecord::Migration
+  def change
+    create_table :homework_detail_manuals do |t|
+      t.float :ta_proportion
+      t.integer  :comment_status
+      t.date :evaluation_start
+      t.date  :evaluation_end
+      t.integer :evaluation_num
+      t.integer :absence_penalty,  default: 1
+      t.integer  :homework_common_id
+
+      t.timestamps
+    end
+  end
+end