hibernate3 的常用操作（批量删除，批量插入，关联查询），hibernate3批量删除,1批量删除是调用sql引

hibernate3 的常用操作（批量删除，批量插入，关联查询），hibernate3批量删除,1批量删除是调用sql引

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```java@Componentpublic 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 &amp;&amp; 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： ```javapublic 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);    }