当我们在使用mybatis的时候，就避免不了批量更新，或者批量查询使用数组或者list，就避免不了使用foreach遍历，当我们在遍历的时候，数据遍历不出来，取出的值是null
如下：只需要修改为下标取值
将jdbc改写为mybatis时，传入的条件为list使用到的标签是<where> 、<choose>、<when>、<if>、<foreach>因为判断list集合时判断条件不全，导致sql执行错误
<where>
<choose>
<when test="unitList != null and ! unitList.isEmpty() and unitList.size() > 0">
(tab2.id IN
<foreach collection="unitList" item="item" index="index"
open="(" separator="," close=")">
#{item}
</foreach>
AND tab1.`status` = #{deviceStatus})
<if test="zoonList != null and ! zoonList.isEmpty() and zoonList.size() > 0">
OR (tab2.leaderId IN
<foreach collection="zoonList" item="item" index="index"
open="(" separator="," close=")">
#{item}
</foreach>
AND tab1.`status` = #{deviceStatus})
</if>
</when>
<when test="zoonList != null and ! zoonList.isEmpty() and zoonList.size() > 0">
tab2.leaderId IN
<foreach collection="zoonList" item="item" index="index"
open="(" separator="," close=")">
#{item}
</foreach>
AND tab1.`status` = #{deviceStatus}
</when>
</choose>
</where>以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
