mybatis異常：Mapped Statements collection does not contain value

在上手mybatis一對多時就遇到了個巨坑：

Mapped Statements collection does not contain value

在網上查了大量資料都無法解決，或者說是我不夠理解那些解決方案。

 <select id="selectComment" resultMap="shareCommentResult">
        select c.*,
               l.id is not null is_like,
               #{param2} as     u_account
        from cat_share_comment c
                 left join cat_share_like l on c.id = l.host_id and l.part_code = 2 and l.account = #{param2}
        where c.host_id = #{param1}
    </select>

<resultMap id="shareCommentResult" type="xyz.ganbug.gdutdemo.model.cat.CatShareCommentVo">
        <id column="id" property="id"/>
        <result column="account" property="account"/>
        <result column="wx_name" property="wxName"/>
        <result column="host_id" property="hostId"/>
        <result column="avatar_url" property="avatarUrl"/>
        <result column="text" property="text"/>
        <result column="like_num" property="likeNum"/>
        <result column="comment_num" property="commentNum"/>
        <result column="is_like" property="isLike"/>
        <result column="create_date" property="createDate"/>
        <result column="create_time" property="createTime"/>
        <result column="timestamp" property="timestamp"/>
        <collection property="comments" ofType="xyz.ganbug.gdutdemo.model.cat.CatShareComment2Vo"
                    select="xyz.ganbug.gdutdemo.mapper.CatShareMapper.selectComment2sForComment"
                    column="{id=id,account=u_account}"/>
    </resultMap>

    <select id="selectComment2sForComment" resultMap="shareComment2">
        select c.*,
               l.id is not null is_like
        from cat_share_comment2 c
                 left join cat_share_like l on c.id = l.host_id and l.part_code = 2 and l.account = '3117002575'
        where c.host_id = #{id}
    </select>

分析：selectComment中select c.*,要注意，我天真的以爲它等同於沒有前綴c.，如c.id 跟 id一樣，事實是在一般的映射中確實如此，都是如果要映射到屬性column中那就大錯特錯了。
所以應該這樣修改：
把

<collection property="comments" ofType="xyz.ganbug.gdutdemo.model.cat.CatShareComment2Vo"
                    select="xyz.ganbug.gdutdemo.mapper.CatShareMapper.selectComment2sForComment"
                    column="{id=id,account=u_account}"/>

修改成（不要忽略前綴c.）

<collection property="comments" ofType="xyz.ganbug.gdutdemo.model.cat.CatShareComment2Vo"
        select="xyz.ganbug.gdutdemo.mapper.CatShareMapper.selectComment2sForComment"
        column="{id=c.id,account=u_account}"/>