Mybatis 返回对象里包含List＜String＞或List＜Long＞集合结果错误

原创已于 2023-04-25 10:15:41 修改 · 2.1k 阅读

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#mybatis #java #数据库

于 2023-04-25 10:14:10 首次发布

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文章描述了一个在使用MyBatis进行SQL查询并映射结果到Java对象时遇到的问题。查询涉及到`advice_no`,`cure_begin_time`,`cure_end_time`和`cure_week_day`字段，原始的`resultMap`配置导致了`cureWeekDay`被解析为Long类型的数组，但缺少`adviceNo`字段时引发空指针异常。通过修改`resultMap`，将`cure_week_day`配置为一个包含结果的集合，问题得到解决，现在`cureWeekDay`正确映射为[2,4,5]这样的数组。

SQL语句：

select distinct
            advice_no,
            time(cure_begin_time) as cure_begin_time,
            time(cure_end_time) as cure_end_time,
            cure_week_day
from cure_schedule where delete_flag=0

SQL查到结果是

mybatis映射文件XML的resultMap是

-------修改前------
<resultMap id="CureInfo"  type="com.aadata.yiyang.entity.request.CureScheduleCreateCureInfo">
    <result property="adviceNo" column="advice_no" />
    <result property="cureBeginTime" column="cure_begin_time" />
    <result property="cureEndTime" column="cure_end_time" />
    <collection property="cureWeekDay" ofType="Long" column="cure_week_day"/> 
</resultMap>

但是返回Java对象是

"adviceNo": "2023040194",
eginTime": "10:00:00",
"cureEndTime": "10:20:00",
"cureWeekDay": [
    2023040194,
    2023040194,
    2023040194
]

如果去掉adviceNo字段则会报空指针错误。

解决方法：

-------修改后------
<resultMap id="CureInfo" type="com.aadata.yiyang.entity.request.CureScheduleCreateCureInfo">
    <result property="adviceNo" column="advice_no" />
    <result property="cureBeginTime" column="cure_begin_time" />
    <result property="cureEndTime" column="cure_end_time" />
    <collection property="cureWeekDay" ofType="Long">
        <result column="cure_week_day"/>
    </collection>
</resultMap>

"adviceNo": "2023040194",
"cureBeginTime": "10:00:00",
"cureEndTime": "10:20:00",
"cureWeekDay": [ 2, 4, 5]

Mybatis 返回对象里包含List＜String＞ 或List＜Long＞集合结果错误

Mybatis 返回对象里包含List＜String＞或List＜Long＞集合结果错误