hibernate-hql-18

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public class HQLThreeTest {    public static SessionFactory sf = null;    @BeforeClass    public static void beforeClass(){        Configuration cfg = new AnnotationConfiguration();        sf = cfg.configure().buildSessionFactory();    }    //  类中的某字段对应的集合是否为空    //  注意设置  @one2many    @Test    public void testHQL_20(){        Session session = sf.getCurrentSession();        session.beginTransaction();        Query q = session.createQuery("  from Topic t where t.msgs is empty ");        List<Topic> topics = (List<Topic>)q.list();        for(Topic t:topics){            System.out.println(t.getTitle());        }        session.getTransaction().commit();    }    @Test    public void testHQL_21(){        Session session = sf.getCurrentSession();        session.beginTransaction();        Query q = session.createQuery("  from Topic t where t.title like '%5' ");        List<Topic> topics = (List<Topic>)q.list();        for(Topic t:topics){            System.out.println(t.getTitle());        }        session.getTransaction().commit();    }    // hql中还可以使用一些函数  不重要    @Test    public void testHQL_22(){        Session session = sf.getCurrentSession();        session.beginTransaction();        Query q = session.createQuery(" select  lower(t.title)," +                "upper(t.title)," +                "trim(t.title)," +                "concat(t.title,'***')," +                "length(t.title)" +                "  from Topic t  ");        for(Object o:q.list()){            Object[] t = (Object[])o;            System.out.println(t[0]+"-"+t[1]);        }        session.getTransaction().commit();    }    @Test    public void testHQL_25(){        Session session = sf.getCurrentSession();        session.beginTransaction();        Query q = session.createQuery(" select current_date ,current_time ,current_timestamp ,t.id from Topic t ");        for(Object o:q.list()){            Object[] t = (Object[])o;            System.out.println(t[0]+"-"+t[1]+"-"+t[2]+"-"+t[3]);        }        session.getTransaction().commit();    }    @Test    public void testHQL_31(){        Session session = sf.getCurrentSession();        session.beginTransaction();        Query q = session.createQuery(" from Topic t where not exists (select m.id from Msg m where t.id = m.topic.id)");        List<Topic> topics = (List<Topic>)q.list();        for(Topic t:topics){            System.out.println(t.getTitle());        }        session.getTransaction().commit();    }    // update    @Test    public void testHQL_32(){        Session session = sf.getCurrentSession();        session.beginTransaction();        Query q = session.createQuery(" update Topic t set t.title = upper(t.title) ");        q.executeUpdate();        q = session.createQuery(" from Topic ");        List<Topic> topics = (List<Topic>)q.list();        for(Topic t:topics){            System.out.println(t.getTitle());        }        session.getTransaction().commit();    }    //  支持命名查询(不重要  好处是方便sql统一管理)    // native query(了解)    @Test    public void testHQL_34(){        Session session = sf.getCurrentSession();        session.beginTransaction();        SQLQuery q = session.createSQLQuery("  select * from category limit 2,4 ").addEntity(Category.class);        List<Topic> topics = (List<Topic>)q.list();        for(Topic t:topics){            System.out.println(t.getTitle());        }        session.getTransaction().commit();    }    @Test    public void testSchemaExport(){        //  true  是否将建表语句输出到控制台   true  是否在数据库中建表        new SchemaExport(new AnnotationConfiguration().configure()).create(true,true);    }    @AfterClass    public static void AfterClass(){        sf.close();    }}
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