java - hibernate 数据获取

Question

这是我获取数据的方式:

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;
    }

问题是当我在数据库中手动更新数据时，获取的数据没有改变。但是当我重新加载服务器和 IDE 时，它就可以工作了。问题的原因可能是什么？我想我以不正确的方式使用了 session 对象。谢谢。

Answer 1

你需要设置CacheMode刷新

query.setCacheMode(CacheMode.REFRESH);

您的查询将类似于 -

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();

但是，在使用 hibernate 时从外部更新 DB 是个坏主意，否则您将无法获得 hibernate 缓存的好处。