mybatis 一对多映射 xml

最近在做一个评论功能时，涉及到一个评论对应多张图片，这个时候想一个方法全部返回，就需要在xml中进行配置。由于好久没用到一对多的配置，所以很长时间才写出来，mark一下

返回对象：

private String commentId;

private String commentContent;

private Date commentTime;

private String productId;

private String userId;

private String userName;

private String headImg;

private Integer startNum;

private Integer supportNum;

private List<CommentImg> commentImgs;

对应xml配置文件：

<mapper namespace="com.lefang.lf.vo.CommentGrid">

<resultMap type="com.lefang.lf.vo.CommentGrid" id="CommentGrid">

<id column="COMMENT_ID" property="commentId" />

<result column="COMMENT_CONTENT" property="commentContent" />

<result column="COMMENT_TIME" property="commentTime" />

<result column="HEAD_IMG" property="headImg" />

<result column="PRODUCT_ID" property="productId" />

<result column="USER_ID" property="userId"/>

<result column="USER_NAME" property="userName"/>

<result column="START_NUM" property="startNum"/>

<result column="SUPPORT_NUM" property="supportNum"/>

<collection property="commentImgs" ofType="com.lefang.lf.model.CommentImg">

<id column="img_id" property="id" />

<result column="img_url" property="imgUrl" />

</collection>

</resultMap>

<select id="grid" resultMap="CommentGrid">

select distinct

C.id COMMENT_ID,

C.COMMENT_CONTENT,

C.COMMENT_TIME,

C.PRODUCT_ID,

C.START_NUM,

C.SUPPORT_NUM,

C.USER_ID,

CI.ID IMG_ID,

CI.IMG_URL

from

L_LF_COMMENT C LEFT JOIN L_LF_COMMENT_IMG CI ON CI.COMMENT_ID = C.ID

where 1 = 1

<if test="productId!=null">

AND C.PRODUCT_ID =#{productId}

</if>

order by COMMENT_TIME desc

</select>

</mapper>