mybatis多表查询返回map类型

秒速五厘米 2022-05-29 12:07 342阅读 0赞

mybatis进行多表查询时，返回的结果为map而不是某个实体类的时候，如下：

<select id="list" parameterType="User" resultType="map">
        SELECT
            u.uid,
            u.role_id,
            m.mid,
            m.mname,
            r.role_id,
            r.mid,
            r.iden
        FROM
            user u
        LEFT JOIN role r ON u.role_id = r.role_id
        LEFT JOIN module m ON r.mid = m.mid
        WHERE
            u.uid = #{uid}
    </select>

DAO中的成员方法：

public List<Map<String, Object>> list(User user, "findListMap");

对返回的List

@Test
    public void listMap() {
        User user = new User();
        user.setUid(1);
        List<Map<String, Object>> listMap = testService.listMap(user, "findListMap");
        for (Map<String, Object> map : listMap) {
            Set<String> set = map.keySet();
            Iterator<String> it = set.iterator();
            while (it.hasNext()) {
                Object key = it.next();
                Object value = map.get(key);
                System.out.println(value);
           }
        }
    }

参考：  
[http://blog.csdn.net/cydbetter/article/details/79074064][http_blog.csdn.net_cydbetter_article_details_79074064]  
[https://blog.csdn.net/lxxxzzl/article/details/43604481][https_blog.csdn.net_lxxxzzl_article_details_43604481]  
[https://blog.csdn.net/GensingU/article/details/74856351][https_blog.csdn.net_GensingU_article_details_74856351]  
[https://blog.csdn.net/chenluyao\_it/article/details/78747859][https_blog.csdn.net_chenluyao_it_article_details_78747859]

[http_blog.csdn.net_cydbetter_article_details_79074064]: http://blog.csdn.net/cydbetter/article/details/79074064
[https_blog.csdn.net_lxxxzzl_article_details_43604481]: https://blog.csdn.net/lxxxzzl/article/details/43604481
[https_blog.csdn.net_GensingU_article_details_74856351]: https://blog.csdn.net/GensingU/article/details/74856351
[https_blog.csdn.net_chenluyao_it_article_details_78747859]: https://blog.csdn.net/chenluyao_it/article/details/78747859