hibernate

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hibernate 查询

hibernate操作的是对象 orm对象关系模型

1.查询一

/**
 * select street.sname,street.sid from Street as street
 * 查询得到的是一个 Object[]
 */
/*List list = session.createQuery("select street.sname,street.sid from Street as street").list();
for (Object[] objects : list) {
System.out.println(objects[0]+"+"+objects[1]+"+");
}*/
/**
 *在Street类里面重写了一个构造方法new Street(street.sname,street.sid)
 * select new Street(street.sname,street.sid) from Street as street
 * 查询得到的是一个Street对象
 */
List list = session.createQuery("select new Street(street.sname,street.sid) from Street as street").list();

 2. 模糊查询

String hql = "from Street as street where street.sname like ?";//占位符
List list = session.createQuery(hql).setString(0, "%海%").list();

 3.参数查询

String hql = "from Street as street where street.sid>3";
List list = session.createQuery(hql).list();

 4.对象关联查询

String hql = "select provinces from Street street,Provinces provinces where street.provinces=provinces and street.sname='山路'";
List list = session.createQuery(hql).list();

 5.分页查询

String hql = "from Street";
Query query = session.createQuery(hql);
query.setFirstResult(0);//开始
query.setMaxResults(3);//页面大小
List list = query.list();

 6.函数统计

String hql = "select count(street) from Street as street";
Query query = session.createQuery(hql);

 7.排序查询

String hql = "select street from Street as street order by street.sid";
Query query = session.createQuery(hql);
List list = query.list();

 8.对象查询

Criteria c = session.createCriteria(Street.class);
	if(null !=street){
	if(null!=street.getSname()){
		c.add(Restrictions.like("sname", street.getSname(),MatchMode.ANYWHERE));//模糊查询。查询  sname 中像 street.getSname()的
	}
	if(0!=street.getSid()){
		c.add(Restrictions.ge("sid",street.getSid()));//street.getSid()大于等于sid
	}
//	if(0!=street.getSid()){
//		c.add(Restrictions.le("sid",street.getSid()));//street.getSid()小于等于sid
//	}
	}
                 c.addOrder(Order.asc("sid"));//可以增加多个排序规则
//	c.addOrder(Order.desc("sid"));//可以增加多个排序规则
	hUtil.sessionClose(session);
return c.list();

 9.查询

Street street = (Street)session.get(Street.class, sid);

 10.添加

Provinces provinces = new Provinces();
provinces.setPid(pid);
provinces.setPname(pname);
session.save(provinces);

 11.更新

street = (Street)session.load(Street.class, sid);
street.setSname(sname);
session.update(street);

 12.删除

Street street = (Street)session.get(Street.class, id);
session.delete(street);