xslt - 使用 Muenchian 方法转置 XML - 多个分组

Question

我需要转置一个 XML 文件，例如：

<?xml version="1.0" encoding="UTF-8"?>
<products>
    <product id="10" name="Widget 1" price="15.99" category_code="T" category="Toys" manufacturer_code="SC1" manufacturer="Some Company 1" />
    <product id="10" name="Widget 1" price="15.99" category_code="E" category="Electronics" manufacturer_code="SC1" manufacturer="Some Company 1" />
    <product id="10" name="Widget 1" price="15.99" category_code="T" category="Toys" manufacturer_code="SC2" manufacturer="Some Company 2" />
    <product id="10" name="Widget 1" price="15.99" category_code="E" category="Electronics" manufacturer_code="SC2" manufacturer="Some Company 2" />
    <product id="10" name="Widget 1" price="15.99" category_code="T" category="Toys" manufacturer_code="SC3" manufacturer="Some Company 3" />
    <product id="10" name="Widget 1" price="15.99" category_code="E" category="Electronics" manufacturer_code="SC3" manufacturer="Some Company 3" />
    <product id="11" name="Widget 2" price="21.99" category_code="V" category="Video Games" manufacturer_code="SC4" manufacturer="Some Company 4" />
    <product id="12" name="Widget 3" price="10.99" category_code="T" category="Toys" manufacturer_code="SC1" manufacturer="Some Company 2" />
</products>

到一个逗号分隔的文本文件，或者一个格式正确的 HTML 表格，其中每个产品只包含一行，如下所示：

id,name,price,category_code_1,category_1,category_code_2,category_2,manufacturer_code_1,manufacturer_1,manufacturer_code_2,manufacturer_2,manufacturer_code_3,manufacturer_3
    10, Widget 1, 15.99, T, Toys, E, Electronics, SC1, Some Company 1, SC2, Some Company 2, SC3, Some Company 3 
    11, Widget 2, 21.99, V, Video Games,,, SC4, Some Company 4,,,,
    12, Widget 3, 10.99, T, Toys,,, SC1, Some Company 2,,,,

正如您所注意到的，XML 数据可以被认为是三个表连接在一起的结果：product、product_category 和 product_manufacturer。每个产品可以属于多个类别并有多个制造商。当然，我正在处理的真实数据更复杂，而且在一个完全不同的领域，但是这个示例正确地描述了这个问题。

我对 XSLT 的了解非常有限，在 SO 和 Internet 上的其他资源的帮助下，我整理了一个样式表，部分提供了我需要的东西：

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="html" version="1.0" encoding="UTF-8" indent="yes"/>
    <xsl:key name="key_product_group" match="product" use="@id"/>
    <xsl:key name="key_category_group" match="product" use="concat(
             @id,
             @category_code,
             @category)"/>
    <xsl:key name="key_manufacturer_group" match="product" use="concat(
             @id,
             @manufacturer_code,
             @manufacturer)"/>
    <xsl:variable name="var_max_category_group"  >
        <xsl:for-each select="//product[generate-id(.) = generate-id(key('key_product_group',@id) )]">
            <xsl:sort select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_category_group',
                                   concat(@id,
                                  @category_code,
                                  @category)))])" order="descending"/>
            <xsl:if test="position() = 1">
                <xsl:value-of select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_category_group',
                                   concat(@id,
                                  @category_code,
                                  @category)))])"/>
            </xsl:if>
        </xsl:for-each>
    </xsl:variable>
    <xsl:variable name="var_max_manufacturer_group">
        <xsl:for-each select="//product[generate-id(.) = generate-id(key('key_product_group',@id) )]">
            <xsl:sort select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_manufacturer_group',
                                   concat(@id,
                                  @category_code,
                                  @category)))])" order="descending"/>
            <xsl:if test="position() = 1">
                <xsl:value-of   select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_manufacturer_group',
                                   concat(@id,
                                  @manufacturer_code,
                                  @manufacturer)))])"/>
            </xsl:if>
        </xsl:for-each>
    </xsl:variable>
    <xsl:template match="/">
        <xsl:text>id,</xsl:text>
        <xsl:text>name,</xsl:text>
        <xsl:text>price,</xsl:text>
        <xsl:call-template name="loop_pcat">
            <xsl:with-param name="count" select="$var_max_category_group"/>
        </xsl:call-template>
        <xsl:call-template name="loop_pmf">
            <xsl:with-param name="count" select="$var_max_manufacturer_group"/>
        </xsl:call-template>
        <br></br>
        <xsl:variable name="var_group"
                          select="//product[generate-id(.) = generate-id(key('key_product_group',@id)[1])]"/>
        <xsl:for-each select="$var_group">
            <xsl:sort order="ascending" select="@id"/>
            <xsl:value-of select="@id"/>,
            <xsl:value-of select="@name"/>,
            <xsl:value-of select="@price"/>,
            <xsl:for-each select="key('key_product_group',@id )[generate-id() = generate-id(key('key_category_group',
                                   concat(@id,
                                  @category_code,
                                  @category)))]">
                <xsl:value-of select="@category_code"/>,
                <xsl:value-of select="@category"/>,
            </xsl:for-each>
            <xsl:for-each select="key('key_product_group',@id )[generate-id() = generate-id(key('key_manufacturer_group',
                                   concat(@id,
                                  @manufacturer_code,
                                  @manufacturer)))]">
                <xsl:value-of select="@manufacturer_code"/>,
                <xsl:value-of select="@manufacturer"/>,
            </xsl:for-each>
            <br></br>
        </xsl:for-each>
    </xsl:template>
    <xsl:template name="loop_pcat">
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count > 0">
            <xsl:value-of select="concat('category_code_',$limit - $count)"/>
            <xsl:text>,</xsl:text>
            <xsl:value-of select="concat('category_',$limit - $count)"/>
            <xsl:text>,</xsl:text>
            <xsl:call-template name="loop_pcat">
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
    <xsl:template name="loop_pmf">
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count > 0">
            <xsl:value-of select="concat('manufacturer_code_',$limit - $count)"/>
            <xsl:text>,</xsl:text>
            <xsl:value-of select="concat('manufacturer_',$limit - $count)"/>
            <xsl:text>,</xsl:text>
            <xsl:call-template name="loop_pmf">
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
</xsl:stylesheet>

上面的样式表产生以下结果：

id,name,price,category_code_1,category_1,category_code_2,category_2,manufacturer_code_1,manufacturer_1,manufacturer_code_2,manufacturer_2,manufacturer_code_3,manufacturer_3,
10, Widget 1, 15.99, T, Toys, E, Electronics, SC1, Some Company 1, SC2, Some Company 2, SC3, Some Company 3, 
11, Widget 2, 21.99, V, Video Games, SC4, Some Company 4, 
12, Widget 3, 10.99, T, Toys, SC1, Some Company 2, 

输出至少有一个主要问题：每一行中都不存在所有列，例如第 2 行和第 3 行缺少 category_code_2、category_2、manufacturer_code 和manufacturer 2 和 3。我确定样式表还有其他问题同样，我不知道它将如何在相对较大的 xml 文件上执行，但现在我非常感谢您在使样式表生成所需的输出格式方面的帮助。

谢谢

耐甲氧西林金黄色葡萄球菌

Answer 1

我已经开始使用我自己的实现，但后来你发布了，我能够重用你的一些代码来加快速度。主要区别在于：

• 在模板中，分隔符添加在前面而不是数据之后；这样，您可以正确地结束您的线路。
• 键仅使用 id 和代码（而不是名称）。
• 键的连接也使用分隔符 ( '#')。
• 主模板仅提供标题行。
• 产品模板对数据模板的调用更简单。
• 相应地修改了数据模板……</li>

这是我生成的样式表及其输出：

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="text" version="1.0" encoding="UTF-8"/>
    <xsl:key name="byProduct" match="product" use="@id"/> 
    <xsl:key name="byProductAndCategory" match="product" use="concat(@id,'#',@category_code)"/> 
    <xsl:key name="byProductAndManufacturer" match="product" use="concat(@id,'#',@manufacturer_code)"/>  
    <xsl:variable name="delimiter" select="','"/>
    <xsl:variable name="eol" select="'&#xa;'"/>
    <xsl:variable name="maxManufacturers">
        <xsl:for-each select="//product[count(.|key('byProduct',@id)[1])=1]">
            <xsl:sort select="count(key('byProductAndCategory',concat(@id,'#',@category_code)))"/>
            <xsl:if test="position()=last()">
                <xsl:value-of select="count(key('byProductAndCategory',concat(@id,'#',@category_code)))"/>
            </xsl:if>
        </xsl:for-each>
    </xsl:variable>
    <xsl:variable name="maxCategories">
        <xsl:for-each select="//product[count(.|key('byProduct',@id)[1])=1]">
            <xsl:sort select="count(key('byProductAndManufacturer',concat(@id,'#',@manufacturer_code)))"/>
            <xsl:if test="position()=last()">
                <xsl:value-of select="count(key('byProductAndManufacturer',concat(@id,'#',@manufacturer_code)))"/>
            </xsl:if>
        </xsl:for-each>
    </xsl:variable>
    <xsl:template match="/">
        <!--create the file header-->
        <xsl:text>id</xsl:text>
        <xsl:value-of select="$delimiter"/>
        <xsl:text>name</xsl:text>
        <xsl:value-of select="$delimiter"/>
        <xsl:text>price</xsl:text>
        <!--recursive loop for each group to add appropriate number of columns, i.e. maximum number of repetitions-->
        <xsl:call-template name="loop_pcat_header">
            <xsl:with-param name="count" select="$maxCategories"/>
        </xsl:call-template>
        <!--recursive loop for each group to add appropriate number of columns, i.e. maximum number of repetitions-->
        <xsl:call-template name="loop_pmf_header">
            <xsl:with-param name="count" select="$maxManufacturers"/>
        </xsl:call-template>
        <xsl:value-of select="$eol"/>
        <xsl:apply-templates select="//product[count(.|key('byProduct',@id)[1])=1]"/>
    </xsl:template>
    <xsl:template match="product">
        <!-- id -->
        <xsl:value-of select="@id"/>
        <xsl:value-of select="$delimiter"/>
        <!-- name -->
        <xsl:value-of select="@name"/>
        <xsl:value-of select="$delimiter"/>
        <!-- price -->
        <xsl:value-of select="@price"/>
        <!-- category stuff -->
        <xsl:call-template name="loop_pcat_data">
            <xsl:with-param name="data" select="key('byProductAndManufacturer',concat(@id,'#',@manufacturer_code))"/>
            <xsl:with-param name="count" select="$maxCategories"/>
        </xsl:call-template>
        <!-- manufacturer stuff -->
        <xsl:call-template name="loop_pmf_data">
            <xsl:with-param name="data" select="key('byProductAndCategory',concat(@id,'#',@category_code))"/>
            <xsl:with-param name="count" select="$maxManufacturers"/>
        </xsl:call-template>
        <xsl:value-of select="$eol"/>
    </xsl:template>
    <!--recursive loop templates for file header and data-->
    <xsl:template name="loop_pcat_header">
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count &gt; 0">
            <xsl:value-of select="$delimiter"/>
            <xsl:value-of select="concat('category_code_',$limit - $count)"/>
            <xsl:value-of select="$delimiter"/>
            <xsl:value-of select="concat('category_',$limit - $count)"/>
            <xsl:call-template name="loop_pcat_header">
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
    <xsl:template name="loop_pmf_header">
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count &gt; 0">
            <xsl:value-of select="$delimiter"/>
            <xsl:value-of select="concat('manufacturer_code_',$limit - $count)"/>
            <xsl:value-of select="$delimiter"/>
            <xsl:value-of select="concat('manufacturer_',$limit - $count)"/>
            <xsl:call-template name="loop_pmf_header">
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
    <xsl:template name="loop_pcat_data">
        <xsl:param name="data"/>
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count &gt; 0">
            <xsl:value-of select="$delimiter"/>
            <xsl:value-of select="$data[$limit - $count]/@category_code"/>
            <xsl:value-of select="$delimiter"/>
            <xsl:value-of select="$data[$limit - $count]/@category"/>
            <xsl:call-template name="loop_pcat_data">
                <xsl:with-param name="data" select="$data"/>
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
    <xsl:template name="loop_pmf_data">
        <xsl:param name="data"/>
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count &gt; 0">
            <xsl:value-of select="$delimiter"/>
            <xsl:value-of select="$data[$limit - $count]/@manufacturer_code"/>
            <xsl:value-of select="$delimiter"/>
            <xsl:value-of select="$data[$limit - $count]/@manufacturer"/>
            <xsl:call-template name="loop_pmf_data">
                <xsl:with-param name="data" select="$data"/>
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
</xsl:stylesheet>

请求的输出：

id,name,price,category_code_1,category_1,category_code_2,category_2,manufacturer_code_1,manufacturer_1,manufacturer_code_2,manufacturer_2,manufacturer_code_3,manufacturer_3
10,Widget 1,15.99,T,Toys,E,Electronics,SC1,Some Company 1,SC2,Some Company 2,SC3,Some Company 3
11,Widget 2,21.99,V,Video Games,,,SC4,Some Company 4,,,,
12,Widget 3,10.99,T,Toys,,,SC1,Some Company 2,,,,

Answer 2

所以这就是我想出的，我仍然要处理最后的额外逗号，还要处理属性值中的单引号或双引号等特殊字符。非常感谢任何有关优化代码的帮助。

以下样式表

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="text" version="1.0" encoding="UTF-8" indent="yes"/>
    <!--Generate keys, first is the product group-->
    <xsl:key name="key_product_group" match="product" use="@id"/>
    <!--Here is keys for groupings that are needed, note concatenation of attributes-->
    <xsl:key name="key_category_group" match="product" use="concat(
             @id,
             @category_code,
             @category)"/>
    <!--another key-->
    <xsl:key name="key_manufacturer_group" match="product" use="concat(
             @id,
             @manufacturer_code,
             @manufacturer)"/>
    <!--we need the maximum number of distinct groups for each product so that can format the layout properly-->
    <xsl:variable name="var_max_category_group"  >
        <xsl:for-each select="//product[generate-id(.) = generate-id(key('key_product_group',@id) )]">
            <xsl:sort select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_category_group',
                                   concat(@id,
                                  @category_code,
                                  @category)))])" order="descending"/>
            <xsl:if test="position() = 1">
                <xsl:value-of select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_category_group',
                                   concat(@id,
                                  @category_code,
                                  @category)))])"/>
            </xsl:if>
        </xsl:for-each>
    </xsl:variable>
    <!--maximum for the second group-->
    <xsl:variable name="var_max_manufacturer_group">
        <xsl:for-each select="//product[generate-id(.) = generate-id(key('key_product_group',@id) )]">
            <xsl:sort select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_manufacturer_group',
                                   concat(@id,
                                  @category_code,
                                  @category)))])" order="descending"/>
            <xsl:if test="position() = 1">
                <xsl:value-of   select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_manufacturer_group',
                                   concat(@id,
                                  @manufacturer_code,
                                  @manufacturer)))])"/>
            </xsl:if>
        </xsl:for-each>
    </xsl:variable>
    <!--delmiter and line break characters defined here-->
    <xsl:variable name="var_delimiter" select="','"/>
    <xsl:variable name="var_line_break" select="'&#xa;'"/>

    <!--main procedure starts here-->
    <xsl:template match="/">
        <!--create the file header-->
        <xsl:text>id</xsl:text>
        <xsl:value-of select="$var_delimiter"/>
        <xsl:text>name</xsl:text>
        <xsl:value-of select="$var_delimiter"/>
        <xsl:text>price</xsl:text>
        <xsl:value-of select="$var_delimiter"/>
        <!--recursive loop for each group to add appropriate number of columns, i.e. maximum number of repetitions-->
        <xsl:call-template name="loop_pcat_header">
            <xsl:with-param name="count" select="$var_max_category_group"/>
        </xsl:call-template>
        <!--recursive loop for each group to add appropriate number of columns, i.e. maximum number of repetitions-->
        <xsl:call-template name="loop_pmf_header">
            <xsl:with-param name="count" select="$var_max_manufacturer_group"/>
        </xsl:call-template>
        <xsl:value-of select="$var_line_break"/>
        <!--select products and order ascending, the ordering is not really needed-->
        <xsl:variable name="var_group"
                          select="//product[generate-id(.) = generate-id(key('key_product_group',@id)[1])]"/>
        <xsl:for-each select="$var_group">
            <xsl:sort order="ascending" select="@id"/>
            <!--select non-repeatable attributes-->
            <xsl:value-of select="@id"/>
            <xsl:value-of select="$var_delimiter"/>
            <xsl:value-of select="@name"/>
            <xsl:value-of select="$var_delimiter"/>
            <xsl:value-of select="@price"/>
            <xsl:value-of select="$var_delimiter"/>
            <!--select repeatable groups for each product-->
            <xsl:for-each select="key('key_product_group',@id )[generate-id() = generate-id(key('key_category_group',
                                   concat(@id,
                                  @category_code,
                                  @category)))]">
                <xsl:value-of select="@category_code"/>
                <xsl:value-of select="$var_delimiter"/>
                <xsl:value-of select="@category"/>
                <xsl:value-of select="$var_delimiter"/>
                <!--count number of groups for each product and add blanks for the difference between the max and current instance-->
                <xsl:variable name="var_max_category_group_instance" select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_category_group',
                                   concat(@id,
                                  @category_code,
                                  @category)))])"/>
                <xsl:call-template name="loop_pcat_data">
                    <xsl:with-param name="count" select="$var_max_category_group - $var_max_category_group_instance"/>
                </xsl:call-template>
            </xsl:for-each>
            <!--select repeatable groups for each product-->
            <xsl:for-each select="key('key_product_group',@id )[generate-id() = generate-id(key('key_manufacturer_group',
                                   concat(@id,
                                  @manufacturer_code,
                                  @manufacturer)))]">
                <xsl:value-of select="@manufacturer_code"/>
                <xsl:value-of select="$var_delimiter"/>
                <xsl:value-of select="@manufacturer"/>
                <xsl:value-of select="$var_delimiter"/>
                <!--count number of groups for each product and add blanks for the difference between the max and current instance-->
                <xsl:variable name="var_max_manufacturer_group_instance" select="count(key('key_product_group',@id )[generate-id() = generate-id(key('key_manufacturer_group',
                                   concat(@id,
                                  @manufacturer_code,
                                  @manufacturer)))])"/>
                <xsl:call-template name="loop_pmf_data">
                    <xsl:with-param name="count" select="$var_max_manufacturer_group - $var_max_manufacturer_group_instance"/>
                </xsl:call-template>
            </xsl:for-each>
            <xsl:value-of select="$var_line_break"/>
        </xsl:for-each>
    </xsl:template>
    <!--recursive loop templates for file header and data-->
    <xsl:template name="loop_pcat_header">
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count > 0">
            <xsl:value-of select="concat('category_code_',$limit - $count)"/>
            <xsl:value-of select="$var_delimiter"/>
            <xsl:value-of select="concat('category_',$limit - $count)"/>
            <xsl:value-of select="$var_delimiter"/>
            <xsl:call-template name="loop_pcat_header">
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
    <xsl:template name="loop_pcat_data">
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count > 0">
            <xsl:value-of select="$var_delimiter"/>
            <xsl:value-of select="$var_delimiter"/>
            <xsl:call-template name="loop_pcat_data">
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
    <xsl:template name="loop_pmf_header">
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count > 0">
            <xsl:value-of select="concat('manufacturer_code_',$limit - $count)"/>
            <xsl:value-of select="$var_delimiter"/>
            <xsl:value-of select="concat('manufacturer_',$limit - $count)"/>
            <xsl:value-of select="$var_delimiter"/>
            <xsl:call-template name="loop_pmf_header">
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
    <xsl:template name="loop_pmf_data">
        <xsl:param name="count" select="1"/>
        <xsl:param name="limit" select="$count+1"/>
        <xsl:if test="$count > 0">
            <xsl:value-of select="$var_delimiter"/>
            <xsl:value-of select="$var_delimiter"/>
            <xsl:call-template name="loop_pmf_data">
                <xsl:with-param name="count" select="$count - 1"/>
                <xsl:with-param name="limit" select="$limit"/>
            </xsl:call-template>
        </xsl:if>
    </xsl:template>
</xsl:stylesheet>

应用于此 XML 时

<?xml version="1.0" encoding="UTF-8"?>
<products>
    <product id="10" name="Widget 1" price="15.99" category_code="T" category="Toys" manufacturer_code="SC1" manufacturer="Some Company 1" />
    <product id="10" name="Widget 1" price="15.99" category_code="E" category="Electronics" manufacturer_code="SC1" manufacturer="Some Company 1" />
    <product id="10" name="Widget 1" price="15.99" category_code="T" category="Toys" manufacturer_code="SC2" manufacturer="Some Company 2" />
    <product id="10" name="Widget 1" price="15.99" category_code="E" category="Electronics" manufacturer_code="SC2" manufacturer="Some Company 2" />
    <product id="10" name="Widget 1" price="15.99" category_code="T" category="Toys" manufacturer_code="SC3" manufacturer="Some Company 3" />
    <product id="10" name="Widget 1" price="15.99" category_code="E" category="Electronics" manufacturer_code="SC3" manufacturer="Some Company 3" />
    <product id="11" name="Widget 2" price="21.99" category_code="V" category="Video Games" manufacturer_code="SC4" manufacturer="Some Company 4" />
    <product id="12" name="Widget 3" price="10.99" category_code="T" category="Toys" manufacturer_code="SC1" manufacturer="Some Company 2" />
</products>

生成以下输出：

id,name,price,category_code_1,category_1,category_code_2,category_2,manufacturer_code_1,manufacturer_1,manufacturer_code_2,manufacturer_2,manufacturer_code_3,manufacturer_3,
10,Widget 1,15.99,T,Toys,E,Electronics,SC1,Some Company 1,SC2,Some Company 2,SC3,Some Company 3,
11,Widget 2,21.99,V,Video Games,,,SC4,Some Company 4,,,,,
12,Widget 3,10.99,T,Toys,,,SC1,Some Company 2,,,,,