java - MyBatis - 在嵌套的 foreach 循环中迭代列表，它是 HashMap 的值

Question

SELECT *
FROM mytable
<foreach item="item" index="index" collection="myhashmap.entrySet()" open=" WHERE (" separator=" OR ("> table.attribute= #{item.key} 
    <foreach item="item2" index="index" collection="#{item.value}" separator=" ," open=" AND table.attribute IN (" close="))">
       #{item2.value} 
         </foreach> 
 </foreach>     

HashMap 上的迭代有效，但列表(在 item.value 中)无效。

Map<Integer, List<Integer>> myhashmap = new HashMap<Integer, List<Integer>>();

{item.value.iterator()} 也不起作用。

Exception:
   org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.builder.BuilderException: Error evaluating expression '#{item.value}'.  Return value ({[5800]=null}) was not iterable.

其中 5800 是列表的整数值

感谢任何帮助!

Answer 1

<foreach item="element" index="index" collection="mySet.entrySet()" open=" WHERE ((" separator=" OR ("> table.attribute1= #{element.key} 
    <foreach item="item" index="index" collection="element.value" separator=" ," open=" AND table.attribute2 IN (" close="))">
       #{item} 
         </foreach> 
 </foreach>  

这帮我修好了!