想让数据库返回 SkuItemSaleAttrVo 实体数据

@ToString
@Data
public class SkuItemSaleAttrVo {

    private Long attrId;
    private String attrName;
    private List<AttrValueWithSkuIdVo> attrValues;
}

@Data
@ToString
public class AttrValueWithSkuIdVo {

    private String attrValue;
    private String skuIds;
}

定义Mapper

List<SkuItemSaleAttrVo> getSaleAttrsBySpuId(@Param("spuId") Long spuId);

定义Dao.xml

<resultMap id="skuItemSaleAttrVo" type="com.feng.mall.product.vo.SkuItemSaleAttrVo">
    <result column="attr_id" property="attrId"></result>
    <result column="attr_name" property="attrName"></result>
    <collection property="attrValues" ofType="com.feng.mall.product.vo.AttrValueWithSkuIdVo">
        <result column="attr_value" property="attrValue"></result>
        <result column="sku_ids" property="skuIds"></result>
    </collection>
</resultMap>

<select id="getSaleAttrsBySpuId" resultMap="skuItemSaleAttrVo">
    select ssav.attr_id,
           ssav.attr_name,
           ssav.attr_value,
           group_concat(distinct info.sku_id) sku_ids
    from pms_sku_info info
             left join pms_sku_sale_attr_value ssav
                       on ssav.sku_id = info.sku_id
    where info.spu_id = #{spuId}
    group by ssav.attr_id, ssav.attr_name, ssav.attr_value
</select>