个人主页，TA的课程显示和课程数量、课程列表不匹配

app/controllers/users_controller.rb

@@ -448,7 +448,7 @@ class UsersController < ApplicationController
 
   def user_courses4show
     query = Course.joins("join members m on #{Course.table_name}.id=m.course_id")
-    query = query.where("m.user_id = ?",@user.id)
+    query = query.where("m.user_id = ?",@user.id).order("#{Course.table_name}.id desc")
     if User.current == @user  #看自己
     else
       if @user.user_extensions!=nil && @user.user_extensions.identity == 0 #看老师
@@ -456,13 +456,12 @@ class UsersController < ApplicationController
         query = query.where("r.role_id in(3,7,9)")
       end
       query = query.where(Course.table_name+".is_public = 1")
-      # or exists (select 1 from courses c2,members m2 where c2.id=m2.course_id and c2.id=#{Course.table_name}.id and m2.user_id= User.current.id)
     end
 
     if params[:lastid]!=nil && !params[:lastid].empty?
-      query = query.where("( (#{Course.table_name}.updated_at=? and #{Course.table_name}.id < ?) or #{Course.table_name}.updated_at<?)",params[:lasttime],params[:lastid],params[:lasttime])
+      query = query.where(" #{Course.table_name}.id < ?",params[:lastid],)
     end
-    @list = query.order("#{Course.table_name}.updated_at desc,#{Course.table_name}.id desc").limit(8).all
+    @list = query.limit(8)
 
     render :layout=>nil
   end