Google app engine 如何通过用户从google数据存储中获取数据?
我在玩谷歌应用程序引擎,但有点问题 该示例显示了如何从数据存储中提取内容:Google app engine 如何通过用户从google数据存储中获取数据?,google-app-engine,jdoql,google-cloud-datastore,Google App Engine,Jdoql,Google Cloud Datastore,我在玩谷歌应用程序引擎,但有点问题 该示例显示了如何从数据存储中提取内容: PersistenceManager pm = PMF.get().getPersistenceManager(); String query = "select from " + Greeting.class.getName(); List<Greeting> greetings = (List<Greeting>) pm.newQuery(query).execute(); 但是,如果我尝试
PersistenceManager pm = PMF.get().getPersistenceManager();
String query = "select from " + Greeting.class.getName();
List<Greeting> greetings = (List<Greeting>) pm.newQuery(query).execute();
但是,如果我尝试以下操作,则不会得到任何结果:
PersistenceManager pm = PMF.get().getPersistenceManager();
String query = "select from " + Greeting.class.getName() + " where author == '" + user.GetEmail() + "'";
List<Greeting> greetings = (List<Greeting>) pm.newQuery(query).execute();
我相信这是一个普通的任务,但我就是不能让它工作-任何帮助感谢 在讨论了谷歌群组后,我发现它是这样工作的:
UserService userService = UserServiceFactory.getUserService();
User user = userService.getCurrentUser();
String select_query = "select from " + Greeting.class.getName();
Query query = pm.newQuery(select_query);
query.setFilter("author == paramAuthor");
query.declareParameters("java.lang.String paramAuthor");
greetings = (List<Greeting>) query.execute(user);
String select_query=“select from”+Greeting.class.getName();
Query Query=pm.newQuery(选择_Query);
setFilter(“author==paramAuthor”);
declareParameters(“java.lang.String paramAuthor”);
问候语=(列表)查询。执行(用户);
JDQL语法令人费解…+1。没有回应。。。星期天你期待什么?。。。那是个阳光明媚的星期天!考虑到这个话题和天气,我真的无法期待任何回应:)
String select_query = "select from " + Greeting.class.getName();
Query query = pm.newQuery(select_query);
query.setFilter("author == paramAuthor");
query.declareParameters("java.lang.String paramAuthor");
greetings = (List<Greeting>) query.execute(user);