XSLT 2.0如何求和每个唯一项目id的总数

Question

请注意，某些ID重复，我只想要每个唯一ID的计数之和。正确的总数是11。

注意：我必须将第一个集上的id编辑为1

输入文件示例：

<?xml version="1.0" encoding="UTF-8"?>
<file>
    <item>
        <id>1</id>
         <count>4</count>
    </item>
    <item>
        <id>2</id>
        <count>7</count>
    </item>
    <item>
        <id>2</id>
        <count>7</count>
    </item>
    <item>
        <id>2</id>
        <count>7</count>
    </item>
</file>

<?xml version="1.0" encoding="UTF-8"?>
<output>
    <totalUniqueItemCount>11</totalUniqueItemCount>
</output>

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xs="http://www.w3.org/2001/XMLSchema">
    
    <xsl:output indent="yes" method="xml"/>
    
    <xsl:template match="/file">
        <output>
            <totalUniqueItemCount>
            
                    <xsl:for-each-group select="item" group-by="id">
                
                        <xsl:value-of select="xs:integer(count)"/>
                
                    </xsl:for-each-group>
            
            </totalUniqueItemCount>
        </output>
    </xsl:template>
    
</xsl:stylesheet>

<xsl:output indent="yes" method="xml"/>

<xsl:template match="/file">
    <output>
        <totalUniqueItemCount>
                
                <xsl:value-of select="sum(item[id ne following-sibling::id]/count)"/>
        
        </totalUniqueItemCount>
    </output>
</xsl:template>

Answer 1

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xsl:output indent="yes" method="xml"/>

<xsl:key name="itemById" match="file/item" use="id"/>

<xsl:template match="/file">
    <output>
        <totalUniqueItemCount>
            <xsl:value-of select="sum(//item[generate-id(.) = generate-id(key('itemById',id)[1])]/count)"/>
        </totalUniqueItemCount>
    </output>
</xsl:template>

</xsl:stylesheet>

https://xsltfiddle.libertydevelopment.net/3MVNT44/1