hibernate3 的常用操作（批量删除，批量插入，关联查询）详解编程语言

1 批量删除是调用sql引擎执行sql语句。批量插入有两种方式，a：自己拼接出一条sql语句 b：利用hibernate的session一级缓存，每多少条刷新缓存存入数据库

@Component 
public class StudentDao extends HibernateDao<Student, Integer> { 
 
    public void deleteByIds(List<?> ids) { 
        String hql = "delete from Student where id in (:ids)"; 
        createQuery(hql).setParameterList("ids", ids).executeUpdate(); 
    } 
 
    public void saveBatch(List<Student> stuList) { 
        if (null != stuList && stuList.size() > 0) { 
            Session session = sessionFactory.openSession(); 
            Transaction tx = session.beginTransaction(); 
            try { 
                for (int i = 0; i < stuList.size(); i++) { 
                    session.save(stuList.get(i)); 
                    if (i % 100 == 0) { // 每一百条刷新并写入数据库 
                        session.flush(); 
                        session.clear(); 
                    } 
                } 
            } catch (HibernateException e) { 
                e.printStackTrace(); 
            }finally{ 
                tx.commit(); 
                session.close(); 
            } 
        } 
    } 
} 
//批量查询，当然hibernate也提供了使用某一个属性查询出集合 
    String hql = "from Goods  where  merchandiseId in (:ids)"; 
    List<Goods> goodsList = goodsDao.createQuery(hql).setParameterList("ids", idList).list();

2 批量插入采用sql时如下：

public void setMappingGoods(Integer merchandiseId,List<Integer> ids) { 
        StringBuilder sb = new StringBuilder(); 
        sb.append("insert into mapping_goods(kid,oid) values "); 
        for(Integer id:ids){ 
            sb.append("("+merchandiseId+","+id+")"+","); 
        } 
        goodsmapDao.getSession().createSQLQuery(sb.substring(0, sb.length()-1)).executeUpdate(); 
    }

3 hql 关联查询:当没有在实体中设置关联关系，而是自己建立的中间表时，可以用hql关联查询数据。

    public List<Goods> getMappingGoods(String kuuid) { 
        if(StringUtils.empty(kuuid)){ 
            return new ArrayList<Goods>(); 
        } 
        String hql = " from Goods g where  g.merchandiseUuid!=? and ( (g.merchandiseUuid in (select mp.kuuid from Goodsmap mp where mp.kuuid=? or mp.ouuid=?)) or (g.merchandiseUuid in (select mp.ouuid from Goodsmap mp where mp.kuuid=? or mp.ouuid=?)))"; 
        return goodsDao.find(hql,kuuid, kuuid,kuuid, kuuid,kuuid); 
    }