已经删除了的课程还显示在新建作业的发布课程列表中

app/helpers/users_helper.rb

@@ -591,7 +591,7 @@ module UsersHelper
     option << "请选择发布作业的课程"
     option << -1
     type << option
-    user.courses.visible.select("courses.*,(SELECT MAX(created_at)  FROM `course_activities` WHERE course_activities.course_id = courses.id) AS a").order("a desc").select{|c| user.allowed_to?(:as_teacher,c)}.each do |course|
+    user.courses.visible.where("is_delete =?", 0).select("courses.*,(SELECT MAX(created_at)  FROM `course_activities` WHERE course_activities.course_id = courses.id) AS a").order("a desc").select{|c| user.allowed_to?(:as_teacher,c)}.each do |course|
       option = []
       option << course.name+"（"+course.time.to_s+course.term+"）"
       option << course.id