mybatis .xml中判断集合是否为空

先看报错信息：org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException:### Error querying database. Cause: com.baomidou.mybatisplus.core.exceptions.Myb

没有岁月可回首啊

4516人浏览 · 2022-04-03 19:42:02

没有岁月可回首啊 · 2022-04-03 19:42:02 发布

先看报错信息：

org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: com.baomidou.mybatisplus.core.exceptions.MybatisPlusException: Failed to process, Error SQL: SELECT count(*) FROM m_work_order_plan mp
   where mp.work_status = 1
   and mp.actual_end_time between ? and ?
           and mp.executor_id in

通过debug和数据追源发现不应该拼接 and mp.executor_id in

排查到问题代码集合判断失败导致拼接多余代码

问题代码：

<if test="dto.executorIds !=null and dto.executorIds!=''">
   and mp.executor_id in
   <foreach collection="dto.executorIds" item="executorId" index="i" open="(" close=")" separator=",">
      #{executorId}
   </foreach>

修正后：

<if test="dto.executorIds !=null and dto.executorIds.size>0">
   and mp.executor_id in
   <foreach collection="dto.executorIds" item="executorId" index="i" open="(" close=")" separator=",">
      #{executorId}
   </foreach>
</if>

问题出现原因：

数组判空问题