java - 应用引擎(JAVA): Updating record

Question

我有以下代码[在 doPost() 中]来编辑现有记录。它没有给出任何错误，但记录未保存。任何想法？或基于单个唯一字段更新现有记录的最佳方式是什么？

     if(sAction.compareToIgnoreCase("S")==0)
     {

         String email = req.getParameter("Email");

         PersistenceManager pm = PMF.get().getPersistenceManager();             
         Query query = pm.newQuery(SMSUser.class);
         query.setFilter("Email == pEmail");
         query.declareParameters("String pEmail");
         List<SMSUser> users = (List<SMSUser>) query.execute(email);
         if(!users.isEmpty())
         {
            Iterator it = users.iterator();
            SMSUser u = (SMSUser) it.next();
            u.ContractPerson = req.getParameter("ContractPerson");
            u.Company = req.getParameter("Company");
            u.Address = req.getParameter("Address");
            u.Phone = req.getParameter("Phone");
            u.Aid = req.getParameter("Aid");
            u.Pin = req.getParameter("Pin");
            u.SenderId = req.getParameter("SenderId");
            u.Url = req.getParameter("Url");
            u.Operater = Integer.parseInt(req.getParameter("Operater"));

            pm.makePersistent(u);
        }
        return;
     }

Answer 1

直接使用 PersistenceManager 持久化元素需要关闭持久化管理器，如 the GAE doc clearly states .