如何使用XPath拆分提取XML中flight-number节点的分段字符串并分别返回结果？

The key thing to know here is that XPath 1.0 can't handle string splitting or node creation—you'll need to use XPath 2.0 or later (or pair it with XSLT/XQuery, which are standard tools for XML transformations). Here's how to get your desired result:

XPath 2.0+ Solution #

You can use the tokenize() function to split the text, then construct new flight-number elements for each segment. Here's the query:

/airline/flight-number ! (
  tokenize(., '–') ! element flight-number {
    attribute flight_id { replace(../@flight_id, '-0102$', concat('-010', position())) },
    text()
  }
)

Let's break this down: #

• tokenize(., '–'): Splits the text content of the original flight-number using the en dash (–) as the separator, giving you the strings "01" and "02".
• element flight-number { ... }: Creates a new flight-number element for each split string.
• attribute flight_id { ... }: Adjusts the flight_id attribute to match your example—we replace the trailing -0102 with -0101 for the first segment and -0102 for the second using position() to track which part we're on.
• text(): Inserts the split segment as the text content of the new element.

Alternative: XSLT (Using XPath Under the Hood) #

If you're working in an environment that supports XSLT (like most XML editors or processing tools), this might be more readable. Here's a minimal stylesheet that does the transformation:

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/airline">
    <airline>
      <!-- Split the flight number text into segments -->
      <xsl:for-each select="flight-number/tokenize(text(), '–')">
        <flight-number>
          <!-- Adjust the flight_id attribute -->
          <xsl:attribute name="flight_id">
            <xsl:value-of select="replace(../@flight_id, '-0102$', concat('-010', position()))"/>
          </xsl:attribute>
          <!-- Insert the split segment as text -->
          <xsl:value-of select="."/>
        </flight-number>
      </xsl:for-each>
    </airline>
  </xsl:template>
</xsl:stylesheet>

Important Notes: #

• Ensure you're using an XPath 2.0+ compliant processor (e.g., Saxon, modern libxml2 builds).
• Double-check the delimiter: your XML uses an en dash (–), not a regular hyphen (-), so make sure the tokenize() function uses the correct character.
• If your flight_id pattern differs from the example, tweak the replace() regex to match your actual structure.

Content of the question originates from Stack Exchange, asked by aye decoder