I. 当这个 XSLT 1.0 解决方案时:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output omit-xml-declaration="no" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:key
name="kCustByNameId"
match="CustomerStatement"
use="concat(Name, '+', ID)" />
<xsl:template match="/*">
<Customers>
<xsl:apply-templates
select="CustomerStatement[
generate-id() =
generate-id(key('kCustByNameId', concat(Name, '+', ID))[1])]" />
</Customers>
</xsl:template>
<xsl:template match="CustomerStatement">
<Customer>
<xsl:copy-of select="Name|ID" />
<Amounts>
<xsl:for-each select="key('kCustByNameId', concat(Name, '+', ID))/Amt">
<Amount>
<xsl:apply-templates />
</Amount>
</xsl:for-each>
</Amounts>
</Customer>
</xsl:template>
</xsl:stylesheet>
...应用于 OP 的原始 XML:
<CustomerStatements>
<CustomerStatement>
<Name>ABC</Name>
<ID>1</ID>
<Amt>10</Amt>
</CustomerStatement>
<CustomerStatement>
<Name>ABC</Name>
<ID>1</ID>
<Amt>20</Amt>
</CustomerStatement>
<CustomerStatement>
<Name>XYZ</Name>
<ID>2</ID>
<Amt>30</Amt>
</CustomerStatement>
<CustomerStatement>
<Name>XYZ</Name>
<ID>2</ID>
<Amt>40</Amt>
</CustomerStatement>
</CustomerStatements>
...产生了想要的结果:
<?xml version="1.0" encoding="UTF-8"?><Customers>
<Customer>
<Name>ABC</Name>
<ID>1</ID>
<Amounts>
<Amount>10</Amount>
<Amount>20</Amount>
</Amounts>
</Customer>
<Customer>
<Name>XYZ</Name>
<ID>2</ID>
<Amounts>
<Amount>30</Amount>
<Amount>40</Amount>
</Amounts>
</Customer>
</Customers>
这里首先要看的是Muenchian Grouping,这是 XSLT 1.0 中普遍接受的对问题进行分组的方法。
二、这是一个更紧凑的 XSLT 2.0 解决方案:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
<xsl:output omit-xml-declaration="no" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="/*">
<Customers>
<xsl:for-each-group select="CustomerStatement" group-by="ID">
<Customer>
<xsl:copy-of select="current-group()[1]/Name|current-group()[1]/ID" />
<Amounts>
<xsl:for-each select="current-group()/Amt">
<Amount>
<xsl:apply-templates />
</Amount>
</xsl:for-each>
</Amounts>
</Customer>
</xsl:for-each-group>
</Customers>
</xsl:template>
</xsl:stylesheet>
在这种情况下,请注意 XSLT 2.0 对for-each-group元素的使用,这消除了对有时冗长且可能令人困惑的 Muenchian Grouping 方法的需要。