潍坊网站建设 58,wordpress 酒店预订,wordpress 搭建电商,常见网站类型大部分现实应用中我们并不需要把数据库中的整行数据都拉出来, 所以要做扩展结果集
笔记: 在实际项目过程中, 先用逆向工程自动生成, 然后再做扩展结果集来满足大部分的现实需要 本节内容应该注意扩展结果集的命名方式
创建一个扩展类ShopCustom, (这样命名可以和Shop在项目树…大部分现实应用中我们并不需要把数据库中的整行数据都拉出来, 所以要做扩展结果集
笔记: 在实际项目过程中, 先用逆向工程自动生成, 然后再做扩展结果集来满足大部分的现实需要 本节内容应该注意扩展结果集的命名方式
创建一个扩展类ShopCustom, (这样命名可以和Shop在项目树里面排列在一起) package io.github.coinsjack.pojo;public class ShopCustom extends Shop {private String shopName;private String shopDesc;public ShopCustom() {}
创建一个mapper接口 ShopMapperCustom package io.github.coinsjack.dao;import io.github.coinsjack.pojo.ShopCustom;public interface ShopMapperCustom {ShopCustom getShopById(Integer id);}
创建对应的映射文件 ?xml version1.0 encodingUTF-8 ?
!DOCTYPE mapperPUBLIC -//mybatis.org//DTD Mapper 3.0//ENhttp://mybatis.org/dtd/mybatis-3-mapper.dtdmapper namespaceio.github.coinsjack.dao.ShopMapperCustomcache/ resultMap idshopResultMap typeShopCustomid columnshop_id propertyid /idresult columnshop_name propertyshopName/resultresult columnshop_desc propertyshopDesc//resultMapselect idgetShopById parameterTypeint resultMapshopResultMap select shop_id, shop_name, shop_descfrom tb_shopwhere shop_id #{id}/select
/mapper
测试 Test
public void testGetShopByIdCustom() {SqlSession session MyBatisUtil.getSqlSession();ShopMapperCustom mapper session.getMapper(ShopMapperCustom.class);System.out.println(mapper.getShopById(29));session.close();
}
结果
2018-12-29 11:33:32,656 [main] DEBUG [io.github.coinsjack.dao.ShopMapperCustom] - Cache Hit Ratio [io.github.coinsjack.dao.ShopMapperCustom]: 0.0 2018-12-29 11:33:33,128 [main] DEBUG [io.github.coinsjack.dao.ShopMapperCustom.getShopById] - Preparing: select shop_id, shop_name, shop_desc from tb_shop where shop_id ? 2018-12-29 11:33:33,237 [main] DEBUG [io.github.coinsjack.dao.ShopMapperCustom.getShopById] - Parameters: 29(Integer) 2018-12-29 11:33:33,309 [main] DEBUG [io.github.coinsjack.dao.ShopMapperCustom.getShopById] - Total: 1 ShopCustom{shopName暴漫奶茶店, shopDesc过来喝喝就知道啦你是我的奶茶}Java知识点
如果父类实现了某接口,子类也会继承接口的实现
