hibernate中SQLQuery的addEntity()和setResultTransformer方法
如果使用原生sql语句进行query查询时,hibernate是不会自动把结果包装成实体的。所以要手动调用addEntity(Class class)等一系列方法。
如session.createSQLQuery(sql).addEntity(Class class);注意hibernate3.0.5不支持,单个参数的addEntity方法
另外,hibernate3.2可以对原生sql 查询使用ResultTransformer。这会返回不受Hibernate管理的实体。
session.createSQLQuery("SELECT NAME, BIRTHDATE FROM CATS")
.setResultTransformer(Transformers.aliasToBean(CatDTO.class))
或setResultTransformer(new AliasToBeanResultTransformer (CatDTO.class))
上面的查询将会返回CatDTO的列表,它将被实例化并且将NAME和BIRTHDAY的值注射入对应的属性或者字段。
http://bbs.xml.org.cn/blog/more.asp?name=lhwork&id=15351
但必须注意,对每一个列都必须addScalar("列名")
既然如此,
那么setResultTransformer与addEntity的区别是什么呢?一个区别是前者支持查任意的列,后者必须用select * from users的形式或select {a.*},{b.*} from a,b where ....。
String hql = "select {cdc.*} " +
"from ta_car_dept cd," +
"ta_cardept_desc cdc " +
"where cd.s_code in ( "+sCode+" )" +
" and cd.type = 1" +
" and cdc.lan_id = 1" +
" and cd.auto_type_id = cdc.auto_type_id ";
List list = session.createSQLQuery(hql).addEntity("cdc", TaCarDeptDesc.class).list();
===========
String hql = "select cd.s_code ,cdc.auto_name " +
"from ta_car_dept cd," +
"ta_cardept_desc cdc " +
"where cd.s_code in ( "+sCode+" )" +
" and cd.type = 1" +
" and cdc.lan_id = 1" +
" and cd.auto_type_id = cdc.auto_type_id ";
List list = session.createSQLQuery(hql).addScalar("s_code", Hibernate.STRING).addScalar("auto_name", Hibernate.STRING).list();