Hibernate数据获取

时间:2016-01-17 15:24:35

标签: java hibernate

以下是我获取数据的方法:

public static List<SubjectSubjectUsersUsers> getAllSubjectUsers()
    {
        List<SubjectSubjectUsersUsers> theList = null;

        Session session = ServiceLocator.getSessionFactory().openSession();

        try{

            theList = session.createSQLQuery("SELECT s.name as subject_name, u.name as user_name, u.surname as user_surname, su.id as id from subjects s "
                    + "join subject_users su on s.id = su.subject_id join users u on su.user_id = u.id")

                    .addScalar("subject_name", StandardBasicTypes.STRING)
                    .addScalar("user_name", StandardBasicTypes.STRING)
                    .addScalar("user_surname", StandardBasicTypes.STRING)
                    .addScalar("id", StandardBasicTypes.LONG)
                    .setResultTransformer(Transformers.aliasToBean(SubjectSubjectUsersUsers.class)).list();


        }catch(Exception e){

            e.printStackTrace();

        }finally{

            session.flush();
            session.close();

        }


        return theList;
    }

问题是当我在DB中手动更新数据时,获取的数据不会更改。但是,当我重新加载服务器和IDE它工作。可能是问题的原因是什么?我想我以不正确的方式使用了会话对象。谢谢。

1 个答案:

答案 0 :(得分:3)

您需要设置CacheMode来刷新

query.setCacheMode(CacheMode.REFRESH);

您的查询将如下所示 -

theList = session.createSQLQuery("SELECT s.name as subject_name, u.name as user_name, u.surname as user_surname, su.id as id from subjects s "
                    + "join subject_users su on s.id = su.subject_id join users u on su.user_id = u.id")

                    .setCacheMode(CacheMode.REFRESH)
                    .addScalar("subject_name", StandardBasicTypes.STRING)
                    .addScalar("user_name", StandardBasicTypes.STRING)
                    .addScalar("user_surname", StandardBasicTypes.STRING)
                    .addScalar("id", StandardBasicTypes.LONG)
                    .setResultTransformer(Transformers.aliasToBean(SubjectSubjectUsersUsers.class)).list();

然而,在使用hibernate时从外部更新数据库是一个坏主意,否则你不会从hibernate缓存中获益。