比较两个XML文件中的价格

Question

<xml>
  <produkt>
    <code>000161</code>
    <name>Test name</name>
    <available>Yes</available>
    <price>19,90</price>
  </produkt>
</xml>

<xml>
  <produkt>
    <code>000161</code>
    <name>Test name</name>
    <available>Yes</available>
    <price>18,90</price>
  </produkt>
</xml>

• 产品由
标识
• 检查产品价格是否改变，如果是，复制元素（仅在本例中）
• 不检查或复制新产品(不存在于older.xml:不复制）

compare.xml

<xml>
  <produkt>
    <code>000161</code>
    <name>Test name</name>
    <available>Yes</available>
    <oldprice>18,90</oldprice>
    <newprice>19,90</newprice>
  </produkt>
</xml>




Answer 1

older.xml

<?xml version="1.0" encoding="UTF-8"?>
<xml>
    <produkt>
        <code>000160</code>
        <name>Product A (only in old list)</name>
        <available>Yes</available>
        <price>9,90</price>
    </produkt>
    <produkt>
        <code>000161</code>
        <name>Product B (price falls)</name>
        <available>Yes</available>
        <price>19,90</price>
    </produkt>
    <produkt>
        <code>000163</code>
        <name>Product D (price rises)</name>
        <available>Yes</available>
        <price>24,90</price>
    </produkt>
    <produkt>
        <code>000164</code>
        <name>Product E (price unchanged)</name>
        <available>Yes</available>
        <price>99,90</price>
    </produkt>
</xml>

newer.xml

<?xml version="1.0" encoding="UTF-8"?>
<xml>
    <produkt>
        <code>000161</code>
        <name>Product B (price falls)</name>
        <available>Yes</available>
        <price>18,90</price>
    </produkt>
    <produkt>
        <code>000162</code>
        <name>Product C (only in new list)</name>
        <available>Yes</available>
        <price>16,90</price>
    </produkt>
    <produkt>
        <code>000163</code>
        <name>Product D (price rises)</name>
        <available>Yes</available>
        <price>28,90</price>
    </produkt>
    <produkt>
        <code>000164</code>
        <name>Product E (price unchanged)</name>
        <available>Yes</available>
        <price>99,90</price>
    </produkt>
</xml>

compare.xsl

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

    <xsl:output indent="yes"/>

    <xsl:template match="xml">
        <xsl:variable name="older" select="document('older.xml')"/>
        <xml>
            <xsl:for-each select="produkt">
                <xsl:variable name="code" select="code"/>
                <xsl:variable name="findProduktByCode" select="$older/xml/produkt[code = $code]"/>
                <xsl:if test="price != $findProduktByCode/price">
                    <produkt>
                        <xsl:copy-of select="code"/>
                        <xsl:copy-of select="name"/>
                        <xsl:copy-of select="available"/>
                        <oldprice>
                            <xsl:value-of select="$findProduktByCode/price"/>
                        </oldprice>
                        <newprice>
                            <xsl:value-of select="price"/>
                        </newprice>
                    </produkt>
                </xsl:if>
            </xsl:for-each>
        </xml>
    </xsl:template>

</xsl:stylesheet>

<?xml version="1.0" encoding="UTF-8"?>
<xml>
   <produkt>
      <code>000161</code>
      <name>Product B (price falls)</name>
      <available>Yes</available>
      <oldprice>19,90</oldprice>
      <newprice>18,90</newprice>
   </produkt>
   <produkt>
      <code>000163</code>
      <name>Product D (price rises)</name>
      <available>Yes</available>
      <oldprice>24,90</oldprice>
      <newprice>28,90</newprice>
   </produkt>
</xml>