XSLT 2.0分组，求和，计数和条件

Question

我有将输入分组，对当前组求和的XSLT，并且仅在总和满足特定条件时才输出记录。 每个组的工作正常，但我无法获得预告片记录的准确记录数。

这是一个示例输入：

<Book_Data>
  <Book_Entry>
    <Book>
      <Book_ID>1</Book_ID>
      <Book_Name>Test1</Book_Name>
    </Book>
    <Sales>
      <Quantity>2</Quantity>
    </Sales>
  <Book_Entry>
  <Book_Entry>
    <Book>
      <Book_ID>1</Book_ID>
      <Book_Name>Test1</Book_Name>
    </Book>
    <Sales>
      <Quantity>3</Quantity>
    </Sales>
  <Book_Entry>
  <Book_Entry>
    <Book>
      <Book_ID>2</Book_ID>
      <Book_Name>Test2</Book_Name>
    </Book>
    <Sales>
      <Quantity>3</Quantity>
    </Sales>
  <Book_Entry>
  <Book_Entry>
    <Book>
      <Book_ID>2</Book_ID>
      <Book_Name>Test2</Book_Name>
    </Book>
    <Sales>
      <Quantity>-3</Quantity>
    </Sales>
  <Book_Entry>
</Book_Data>

这是一个示例XSLT（2.0）：

<xsl:for-each-group select="Book_Data/Book_Entry" group-by="Book/Book_ID">
        <xsl:if test="sum(current-group()/Sales/Quantity) != 0">
            <xsl:value-of select="Book/Book_ID"/>
            <xsl:value-of select="Book/Book_Name"/>
        </xsl:if>
</xsl:for-each-group>

<xsl:value-of select="count(distinct-values(Book_Data/Book_Entry/Book/Book_ID[sum(../../Sales/Quantity) != 0]))"/>

问题是顶部正确地仅输出书籍1。但是预告片同时计数了两本书，我无法弄清楚如何在外部上下文中调节总和以引用Book_ID。

Answer 1

如果可以理解，您可以将for-each-group的结果输出存储在变量中，然后计算组数：

    <xsl:variable name="groups" as="xs:string*">
        <xsl:for-each-group select="Book_Data/Book_Entry" group-by="Book/Book_ID">
            <xsl:if test="sum(current-group()/Sales/Quantity) != 0">
                <xsl:sequence select="current-grouping-key()"/>
            </xsl:if>
        </xsl:for-each-group>          
    </xsl:variable>

    <xsl:value-of select="$groups"/>
    <xsl:value-of select="count($groups)"/>