Mybatis返回值封装在Map集合中

数据库表:

CREATE TABLE `Products` (   `prod_id` char(10) COLLATE utf8_unicode_ci NOT NULL,   `vend_id` char(10) COLLATE utf8_unicode_ci NOT NULL,   `prod_name` char(255) COLLATE utf8_unicode_ci NOT NULL,   `prod_price` decimal(8,2) NOT NULL,   `prod_desc` text COLLATE utf8_unicode_ci,   PRIMARY KEY (`prod_id`),   KEY `FK_Products_Vendors` (`vend_id`),   CONSTRAINT `FK_Products_Vendors` FOREIGN KEY (`vend_id`) REFERENCES `Vendors` (`vend_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci

映射文件:

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper     PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"     "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.heiketu.testpackage.mapper.ProductsMapper">  <select id="getResultUseMap" resultType="map">     SELECT * FROM Products WHERE prod_id = #{prod_id} </select> </mapper>

映射接口:

public interface ProductsMapper {     //结果集以Map形式返回     public Map<String,Object> getResultUseMap(@Param("prod_id") String productId); }

测试代码:

SqlSession sqlSession = null;  try {     String configFile = "mybatis-config.xml";     InputStream inputStream = Resources.getResourceAsStream(configFile);     SqlSessionFactory build = new SqlSessionFactoryBuilder().build(inputStream);     sqlSession = build.openSession();      //以Map形式返回     ProductsMapper mapper = sqlSession.getMapper(ProductsMapper.class);     Map<String, Object> useMap = mapper.getResultUseMap("BR03");      //返回形式是key=字段名，value=字段的值     System.out.println(useMap);  } catch (IOException e) {     e.printStackTrace(); }finally {     sqlSession.close(); }

结果:

{vend_id=BRS01, prod_desc=18 inch teddy bear, comes with cap and jacket, prod_price=11.99, prod_id=BR03, prod_name=18 inch teddy bear}

总结:
mybatis映射返回值封装成Map需要在映射文件中的resultType属性值设置为map(map为mybatis默认设置的Map集合类别名).
封装的结果结构为: {key=字段名，value=字段的值,key=字段名，value=字段的值...}

文章来源: Mybatis返回值封装在Map集合中