hibernate怎么实现多表联合查询

参考如下
例如：student表和score表需要做联合查询。
1）sql: select s.id,s.name,sc.score from student as s,score as sc where s.id = sc.userId;
（字段都是用的数据库中字段名称）
2）HQL: select s.id,s.name,sc.score from Student as s,Score as sc where s.id = sc.userId;
(上面字段都是 javabean的属性)
如果按1）查询的话，必须调用 session.createSQLQuery();方法
如果按2）查询，还是调用 session.createQuery();
只是要注意，平时查询的时候，例如：“from Student ”查询的结果集 封装的全都是student对象，但是2）执行的结果集里面不是对象，而是一系列数组。需要转换成需要的样式。
下面 是查询的一段代码：
Session session = getHibernateTemplate().getSessionFactory()
.getCurrentSession();
StringBuffer sb = new StringBuffer(" select user.username,user.truename,user.sex,user.idnum,user.level,s.sumScore from Score as s,Examuser as user where s.id.userId = user.id ");
if(score != null){
if(score.getExamId()!=null && !"".equals(score.getExamId())
&& !"null".equals(score.getExamId())){
sb.append(" and s.examId =:examId ");
}
if(score.getExamPlace()!=null && !"".equals(score.getExamPlace())
&& !"null".equals(score.getExamPlace())){
sb.append(" and s.examPlace =:examPlace ");
}
if(score.getUsername()!=null && !"".equals(score.getUsername())
&& !"null".equals(score.getUsername())){
sb.append(" and s.username like:username ");
}
}
sb.append(" order by s.sumScore desc ");
Query q = session.createQuery(sb.toString());
if(score != null){
if(score.getExamId()!=null && !"".equals(score.getExamId())
&& !"null".equals(score.getExamId())){
q.setParameter("examId",score.getExamId());
}
if(score.getExamPlace()!=null && !"".equals(score.getExamPlace())
&& !"null".equals(score.getExamPlace())){
q.setParameter("examPlace",score.getExamPlace());
}
if(score.getUsername()!=null && !"".equals(score.getUsername())
&& !"null".equals(score.getUsername())){
q.setParameter("username","%"+score.getUsername()+"%");
}
}
List list = q.list();
需要将查询的结果集 进行一下转换：
List stuList = scoreService.findAllScore(queryScore, null); // 返回的结果集
if(stuList != null && stuList.size()>0){
list = new LinkedList();
StudentScore st;
for(int i = 0; i < stuList.size();i++){
st = new StudentScore();
Object[] object = (Object[])stuList.get(i);// 每行记录不在是一个对象 而是一个数组
String userId = (String)object[0];
String username = (String)object[1];
String truename = (String)object[2];
String sex = (String)object[3];
String idnum = (String)object[4];
String level = (String)object[5];
Double sumScore = Double.parseDouble(String.valueOf(object[6]));
String paperId = (String)object[7];
// 重新封装在一个javabean里面
st.setUserId(userId);
st.setUsername(username);
st.setTruename(truename);
st.setIdnum(idnum);
st.setLevel(DictSwitch.getValue("DICT_LEVEL",level));
st.setSex(DictSwitch.getValue("DICT_SEX",sex));
st.setPaperId(paperId);
st.setSumScore(sumScore);
st.setExamplace(DictSwitch.getValue("DICT_EXAMSTATION",examplace));
list.add(st); // 最终封装在list中 传到前台。
}