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Hibernate5.2之原生SQL查询
一. 介绍
在上一篇博客中笔者通过代码的形式给各位读者介绍了Hibernate中最重要的检索方式--HQL查询。在本博文中笔者将向各位读者介绍Hibernate中的原生SQL查询，虽为原生SQL查询，但是笔者认为Hibernate在针对不同的数据库在分页语句的处理上做的很不错，我们不用去关心使用的是何种的数据库。本博文会沿用《Hibernate5.2之HQL查询》中的POJO类和配置文件，请各位看官在阅读本博文之前请先阅读该文章，本篇文章会将HQL中涉及的相关操作原封不动的全部改为SQL查询，所以在代码上的重复度比较的高，请各位读者勿喷，那我们就直接上单元测试了。
二. 单元测试
A.获取所有的Order对象，得到一个List集合
@Test public void list(){ String sql = "select * from orders"; NativeQuery<Order> query = session.createNativeQuery(sql, Order.class); List<Order> list = query.getResultList(); for(Order o : list){ System.out.println(o.getId() + "::" + o.getOrderId()); } }
B.获取Order的分页数据，得到一个List集合
/** * 虽然为原生的SQL查询，但是依然可以使用setFirstResult()和setMaxResults()方法。从而屏蔽了 * 底层数据库的差异性。 */ @Test public void pageList(){ String sql = "select * from orders"; //setFirstResult()从0开始 Query<Order> query = session.createNativeQuery(sql, Order.class).setFirstResult(1).setMaxResults(4); List<Order> list = query.getResultList(); for(Order o : list){ System.out.println(o.getId()); } }
C.多条件查询，返回List集合(第一种形式：索引占位符)
@Test public void multiCretiera(){ String sql = "select * from orders where create_time between ? and ? and order_id like ?"; Query<Order> query = session.createNativeQuery(sql, Order.class); String beginDateStr = "2016-07-26 00:00:00"; String endDateStr = "2016-07-28 23:59:59"; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"); Date beginDate = null; Date endDate = null; try { beginDate = sdf.parse(beginDateStr); endDate = sdf.parse(endDateStr); } catch (ParseException e) { e.printStackTrace(); } //分页从0开始 query.setParameter(0, beginDate).setParameter(1, endDate).setParameter(2, "%D%").setFirstResult(0).setMaxResults(1); List<Order> list = query.getResultList(); for(Order o : list){ System.out.println(o.getOrderId() + "::" + o.getCreateTime()); } }
D.多条件查询，返回List集合(第二种形式：命名占位符)
@Test public void multiCretiera1(){ String sql = "select * from orders where order_id like :orderId and create_time between :beginDate and :endDate"; Query<Order> query = session.createNativeQuery(sql, Order.class); String beginDateStr = "2016-07-26 00:00:00"; String endDateStr = "2016-07-28 23:59:59"; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"); Date beginDate = null; Date endDate = null; try { beginDate = sdf.parse(beginDateStr); endDate = sdf.parse(endDateStr); } catch (ParseException e) { e.printStackTrace(); } query.setParameter("orderId", "%D%").setParameter("beginDate", beginDate).setParameter("endDate", endDate); List<Order> list = query.getResultList(); for(Order o : list){ System.out.println(o.getId() + "::" + o.getOrderId()); }
}
E.大于条件的查询，使用索引占位符
@Test public void gt(){ String sql = "select * from orders where id > ?"; Query<Order> query = session.createNativeQuery(sql, Order.class).setParameter(0, 3); List<Order> list = query.getResultList(); for(Order o : list){ System.out.println(o.getId() + "::" + o.getOrderId()); } }
F.删除操作
@Test public void delete(){ String sql = "delete from orders where id in (:idList)"; Transaction tx = session.beginTransaction(); List<Integer> list = new ArrayList<Integer>(); list.add(1); list.add(2); Query<?> query = session.createNativeQuery(sql).setParameter("idList", list); int i = query.executeUpdate(); System.out.println(i); tx.commit(); session.close(); }
G.获取某一列的值
@Test public void singleValue(){ String sql = "select order_id from orders"; Query<String> query = session.createNativeQuery(sql); List<String> list = query.getResultList(); for(String str : list){ System.out.println(str); } }
H.获取关联对象的结果集
@Test public void getCustomer(){ String sql = "select c.* from orders o join customer c on o.customer_id = c.id where c.id = 8"; Query<Customer> query = session.createNativeQuery(sql, Customer.class); List<Customer> list = query.getResultList(); for(Customer o : list){ System.out.println(o.getId() + ";;"); } }
I.多列数据的查询
@Test public void getObjectArray(){ String sql = "select c.name, c.phone_number, o.order_id, o.create_time from orders o join customer c on o.customer_id = c.id"; Query<Object[]> query = session.createNativeQuery(sql); List<Object[]> list = query.getResultList(); for(Object[] o : list){ System.out.println(o[0] + ";;" + o[1] + ";;" + o[2]); } }
J.函数查询
@Test public void functionQuery(){ String sql = "select max(id), count(*) from orders"; Query<Object[]> query = session.createNativeQuery(sql); Object[] obj = query.getSingleResult(); System.out.println(obj[0] + "::" + obj[1]); }
K.排序
@Test public void descQuery(){ String sql = "select * from orders order by id desc"; Query<Order> query = session.createNativeQuery(sql, Order.class); List<Order> list = query.getResultList(); for(Order o : list){ System.out.println(o.getId() + "::" + o.getOrderId()); } }
L.右连接
@Test public void rightJoin(){ String sql = "select c.* from orders o right join customer c on o.customer_id = c.id"; Query<Customer> query = session.createNativeQuery(sql, Customer.class); List<Customer> list = query.getResultList(); for(Customer c : list){ System.out.println(c.getId()); } }
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原文地址：http://www.cnblogs.com/miller-zou/p/5720048.html
