使用XSLT筛选非空customer_number公共值并按组生成Record标签

需求说明 #

基于XML的<customer_number>字段进行分组输出：

• 非空重复值对应的所有<Customer>节点统一放入一个<Record>
• 单个非空值、空值的每个<Customer>节点各自单独放入一个<Record>

输入Payload #

<?xml version='1.0' encoding='UTF-8'?>
    <CustomerRecord>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>GARY</chargename>
            <customer_number>EP10025</customer_number>
        </Customer>
        <Customer>
            <chargeto>XYZ</chargeto>
            <chargename>DAV</chargename>
            <customer_number></customer_number>
        </Customer>
        <Customer>
            <chargeto>CDE</chargeto>
            <chargename>GARY DAVIS</chargename>
            <customer_number></customer_number>
        </Customer>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>DAV</chargename>
            <customer_number>EP10024</customer_number>
        </Customer>
        <Customer>
            <chargeto>CDE</chargeto>
            <chargename>GARY DAVIS</chargename>
            <customer_number>EP10025</customer_number>
        </Customer>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>DAV</chargename>
            <customer_number>EP10022</customer_number>
        </Customer>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>XYZ</chargename>
            <customer_number>EP10023</customer_number>
        </Customer>
        <Customer>
            <chargeto>CDE</chargeto>
            <chargename>GARY DAVIS</chargename>
            <customer_number>EP10025</customer_number>
        </Customer>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>DAV</chargename>
            <customer_number>EP10023</customer_number>
        </Customer>
    </CustomerRecord>

预期输出 #

<?xml version="1.0" encoding="UTF-8"?>
<Root>
    <Record>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>GARY</chargename>
            <customer_number>EP10025</customer_number>
        </Customer>
        <Customer>
            <chargeto>CDE</chargeto>
            <chargename>GARY DAVIS</chargename>
            <customer_number>EP10025</customer_number>
        </Customer>
        <Customer>
            <chargeto>CDE</chargeto>
            <chargename>GARY DAVIS</chargename>
            <customer_number>EP10025</customer_number>
        </Customer>
    </Record>
    <Record>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>DAV</chargename>
            <customer_number>EP10023</customer_number>
        </Customer>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>XYZ</chargename>
            <customer_number>EP10023</customer_number>
        </Customer>
    </Record>
    <Record>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>DAV</chargename>
            <customer_number>EP10024</customer_number>
        </Customer>
    </Record>
    <Record>
        <Customer>
            <chargeto>ABC</chargeto>
            <chargename>DAV</chargename>
            <customer_number>EP10022</customer_number>
        </Customer>
    </Record>
    <Record>
        <Customer>
            <chargeto>XYZ</chargeto>
            <chargename>DAV</chargename>
            <customer_number/>
        </Customer>
    </Record>
    <Record>
        <Customer>
            <chargeto>CDE</chargeto>
            <chargename>GARY DAVIS</chargename>
            <customer_number/>
        </Customer>
    </Record>
</Root>

现有XSLT代码问题 #

当前XSLT将所有单个节点放入同一个<Record>，不符合每个单个节点各占一个<Record>的要求：

<xsl:stylesheet version="2.0" 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
    
    <xsl:template match="/CustomerRecord">
        <xsl:variable name="groups">
            <xsl:for-each-group select="Customer" group-by="customer_number">
                <group size="{count(current-group())}">
                    <xsl:copy-of select="current-group()"/>
                </group>
            </xsl:for-each-group>
        </xsl:variable>
        <Root>
            <xsl:for-each select="$groups/group[@size > 1]">
                <Record>
                    <xsl:copy-of select="Customer"/>
                </Record>
            </xsl:for-each>
            <Record>
                <xsl:copy-of select="$groups/group[@size = 1]/Customer"/>
            </Record>
        </Root>
    </xsl:template>
    
</xsl:stylesheet>

修正后的XSLT代码 #

<xsl:stylesheet version="2.0" 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
    
    <xsl:template match="/CustomerRecord">
        <Root>
            <!-- 处理重复值分组：每个分组生成一个Record -->
            <xsl:for-each-group select="Customer" group-by="customer_number">
                <xsl:if test="count(current-group()) > 1">
                    <Record>
                        <xsl:copy-of select="current-group()"/>
                    </Record>
                </xsl:if>
            </xsl:for-each-group>
            
            <!-- 处理单个值：每个Customer单独生成一个Record -->
            <xsl:for-each-group select="Customer" group-by="customer_number">
                <xsl:if test="count(current-group()) = 1">
                    <Record>
                        <xsl:copy-of select="current-group()"/>
                    </Record>
                </xsl:if>
            </xsl:for-each-group>
        </Root>
    </xsl:template>
    
</xsl:stylesheet>

修正说明 #

1. 移除了中间变量groups，直接通过两次<xsl:for-each-group>完成逻辑：
   • 第一次遍历分组，筛选成员数大于1的分组，每个分组生成一个<Record>，包含该组所有<Customer>节点
   • 第二次遍历分组，筛选成员数等于1的分组，每个分组生成独立<Record>，仅包含该组唯一的<Customer>节点
2. 该逻辑既满足重复值组合并入单个Record的要求，也保证单个值（包括空值）每个都独立生成Record，完全匹配预期输出。

内容的提问来源于stack exchange，提问作者ABC