solr中dateimport.xml的一对多关系改怎么设计呢?

[海澜百丈冰]

<dataConfig>
<dataSource driver="org.hsqldb.jdbcDriver" url="jdbc:hsqldb:/temp/example/ex" user="sa" />
    <document name="products">
        <entity name="item" query="select * from item">
            <field column="ID" name="id" />
            <field column="NAME" name="name" />
            <field column="MANU" name="manu" />
            <field column="WEIGHT" name="weight" />
            <field column="PRICE" name="price" />
            <field column="POPULARITY" name="popularity" />
            <field column="INSTOCK" name="inStock" />
            <field column="INCLUDES" name="includes" />

            <entity name="feature" query="select description from feature where item_id='${item.ID}'">
                <field name="features" column="description" />
            </entity>
            <entity name="item_category" query="select CATEGORY_ID from item_category where item_id='${item.ID}'">
                <entity name="category" query="select description from category where id = '${item_category.CATEGORY_ID}'">
                    <field column="description" name="cat" />
                </entity>
            </entity>
        </entity>
    </document>
</dataConfig>

我看了官网这么写，但是我觉得有点不符合常规的数据库设计啊，居然把多的放外面，少的放里面。我现在写的是商品类和商品一对多的关系，不知有哪位大神能指点