diff --git a/app/controllers/managements_controller.rb b/app/controllers/managements_controller.rb
index 093b3e4e..b3d944f5 100644
--- a/app/controllers/managements_controller.rb
+++ b/app/controllers/managements_controller.rb
@@ -2084,7 +2084,7 @@ end
     @school_id = params[:school_id]
 
     if params[:school_id] && params[:school_id] != ''
-      @courses = @courses.joins("join user_extensions ue on courses.tea_id = ue.user_id").where("ue.school_id = #{params[:school_id]}")
+      @courses = @courses.where(school_id: params[:school_id])
     end
 
     if params[:homepage_show]