MyBatis注解开发

MyBatis常用注解

注解	对应XML	说明
@Insert	< insert>	新增SQL
@Update	< update>	更新SQL
@Delete	< delete>	删除SQL
@Select	< select>	查询SQL
@Param	–	参数映射
@Results	< resultMap>	结果映射
@Result	< id>< result>	字段映射

开发流程：
1.dao包下创建接口

public interface GoodsDAO {@Select("select * from t_goods where current_price between  #{min} and #{max} order by current_price limit 0,#{limt}")public List<Goods> selectByPriceRange(@Param("min") Float min ,@Param("max") Float max ,@Param("limt") Integer limt);@Insert("INSERT INTO t_goods(title, sub_title, original_cost, current_price, discount, is_free_delivery, category_id) VALUES (#{title} , #{subTitle} , #{originalCost}, #{currentPrice}, #{discount}, #{isFreeDelivery}, #{categoryId})")//<selectKey>@SelectKey(statement = "select last_insert_id()" , before = false , keyProperty = "goodsId" , resultType = Integer.class)public int insert(Goods goods);@Select("select * from t_goods")//<resultMap>@Results({//<id>@Result(column = "goods_id" ,property = "goodsId" , id = true) ,//<result>@Result(column = "title" ,property = "title"),@Result(column = "current_price" ,property = "currentPrice")})public List<GoodsDTO> selectAll();

2.mybatis-config.xml中添加mapper

<mapper class="dao.GoodsDAO"/>

<package name="dao"/>

3.测试查询方法selectByPriceRange

 	@Testpublic void testSelectByPriceRange() throws Exception {SqlSession session = null;try{session = MyBatisUtils.openSession();GoodsDAO goodsDAO = session.getMapper(GoodsDAO.class);List<Goods> list = goodsDAO.selectByPriceRange(100f, 500f, 20);System.out.println(list.size());}catch (Exception e){throw e;} finally {MyBatisUtils.closeSession(session);}}

4.测试插入方法insert

	@Testpublic void testInsert() throws Exception {SqlSession session = null;try{session = MyBatisUtils.openSession();Goods goods = new Goods();goods.setTitle("测试商品");goods.setSubTitle("测试子标题");goods.setOriginalCost(200f);goods.setCurrentPrice(100f);goods.setDiscount(0.5f);goods.setIsFreeDelivery(1);goods.setCategoryId(43);GoodsDAO goodsDAO = session.getMapper(GoodsDAO.class);//insert()方法返回值代表本次成功插入的记录总数int num = goodsDAO.insert(goods);session.commit();//提交事务数据System.out.println(goods.getGoodsId());}catch (Exception e){if(session != null){session.rollback();//回滚事务}throw e;}finally {MyBatisUtils.closeSession(session);}}

5.测试结果映射

	@Testpublic void testSelectAll() throws Exception {SqlSession session = null;try{session = MyBatisUtils.openSession();GoodsDAO goodsDAO = session.getMapper(GoodsDAO.class);List<GoodsDTO> list = goodsDAO.selectAll();System.out.println(list.size());}catch (Exception e){throw e;} finally {MyBatisUtils.closeSession(session);}}