消息查询代码优化

app/controllers/users_controller.rb

@@ -114,14 +114,13 @@ class UsersController < ApplicationController
      else
       case params[:type]
         when 'homework'
-          @user_course_messages = @user.course_messages.reverse.select{|x| x.course_message_type == "HomeworkCommon"}
-          #@user_course_messages = ForgeMessage.find_by_sql("select * from course_messages where user_id='#{@user.id}' and course_message_type = 'HomeworkCommon' order by created_at desc;")
+          @user_course_messages = CourseMessage.where(:course_message_type => "HomeworkCommon", :user_id => @user)
         when 'message'
-          @user_course_messages = @user.course_messages.reverse.select{|x| x.course_message_type == "Message"}
+          @user_course_messages = CourseMessage.where(:course_message_type => "Message", :user_id => @user)
         when 'news'
-          @user_course_messages = @user.course_messages.reverse.select{|x| x.course_message_type == "News"}
+          @user_course_messages = CourseMessage.where(:course_message_type => "News", :user_id => @user)
         when 'poll'
-          @user_course_messages = @user.course_messages.reverse.select{|x| x.course_message_type == "Poll"}
+          @user_course_messages = CourseMessage.where(:course_message_type => "Poll", :user_id => @user)
       end
      end
         respond_to do |format|