我想知道如何在 xml 文档中遍历 xsl:for-each 时选择第一次出现的行数据。

如果假设 xml 文档是这样的:

<catalog>
    <cd>
        <title>Empire Burlesque</title>
        <artist>Bob Dylan</artist>
        <country>USA</country>
        <company>Columbia</company>
        <price>10.90</price>
        <year>1985</year>
    </cd>
    <cd>
        <title>Hide your heart</title>
        <artist>Bonnie Tyler</artist>
        <country>UK</country>
        <company>CBS Records</company>
        <price>9.90</price>
        <year>1988</year>
    </cd>
    <cd>
        <title>Greatest Hits</title>
        <artist>Dolly Parton</artist>
        <country>USA</country>
        <company>RCA</company>
        <price>9.90</price>
        <year>1982</year>
    </cd>
    <cd>
        <title>Still got the blues</title>
        <artist>Gary Moore</artist>
        <country>UK</country>
        <company>Virgin records</company>
        <price>10.20</price>
        <year>1990</year>
    </cd>
    <cd>
        <title>Eros</title>
        <artist>Eros Ramazzotti</artist>
        <country>EU</country>
        <company>BMG</company>
        <price>9.90</price>
        <year>1997</year>
    </cd>
    <cd>
        <title>One night only</title>
        <artist>Bee Gees</artist>
        <country>UK</country>
        <company>Polydor</company>
        <price>10.90</price>
        <year>1998</year>
    </cd>
    <cd>
        <title>Sylvias Mother</title>
        <artist>Dr.Hook</artist>
        <country>UK</country>
        <company>CBS</company>
        <price>8.10</price>
        <year>1973</year>
    </cd>
    <cd>
        <title>Maggie May</title>
        <artist>Rod Stewart</artist>
        <country>UK</country>
        <company>Pickwick</company>
        <price>8.50</price>
        <year>1990</year>
    </cd>
    <cd>
        <title>Romanza</title>
        <artist>Andrea Bocelli</artist>
        <country>EU</country>
        <company>Polydor</company>
        <price>10.80</price>
        <year>1996</year>
    </cd>
    <cd>
        <title>When a man loves a woman</title>
        <artist>Percy Sledge</artist>
        <country>USA</country>
        <company>Atlantic</company>
        <price>8.70</price>
        <year>1987</year>
    </cd>
    <cd>
        <title>Black angel</title>
        <artist>Savage Rose</artist>
        <country>EU</country>
        <company>Mega</company>
        <price>10.90</price>
        <year>1995</year>
    </cd>
    <cd>
        <title>1999 Grammy Nominees</title>
        <artist>Many</artist>
        <country>USA</country>
        <company>Grammy</company>
        <price>10.20</price>
        <year>1999</year>
    </cd>
    <cd>
        <title>For the good times</title>
        <artist>Kenny Rogers</artist>
        <country>UK</country>
        <company>Mucik Master</company>
        <price>8.70</price>
        <year>1995</year>
    </cd>
    <cd>
        <title>Big Willie style</title>
        <artist>Will Smith</artist>
        <country>USA</country>
        <company>Columbia</company>
        <price>9.90</price>
        <year>1997</year>
    </cd>
    <cd>
        <title>Tupelo Honey</title>
        <artist>Van Morrison</artist>
        <country>UK</country>
        <company>Polydor</company>
        <price>8.20</price>
        <year>1971</year>
    </cd>
    <cd>
        <title>Soulsville</title>
        <artist>Jorn Hoel</artist>
        <country>Norway</country>
        <company>WEA</company>
        <price>7.90</price>
        <year>1996</year>
    </cd>
    <cd>
        <title>The very best of</title>
        <artist>Cat Stevens</artist>
        <country>UK</country>
        <company>Island</company>
        <price>8.90</price>
        <year>1990</year>
    </cd>
    <cd>
        <title>Stop</title>
        <artist>Sam Brown</artist>
        <country>UK</country>
        <company>A and M</company>
        <price>8.90</price>
        <year>1988</year>
    </cd>
    <cd>
        <title>Bridge of Spies</title>
        <artist>T`Pau</artist>
        <country>UK</country>
        <company>Siren</company>
        <price>7.90</price>
        <year>1987</year>
    </cd>
    <cd>
        <title>Private Dancer</title>
        <artist>Tina Turner</artist>
        <country>UK</country>
        <company>Capitol</company>
        <price>8.90</price>
        <year>1983</year>
    </cd>
    <cd>
        <title>Midt om natten</title>
        <artist>Kim Larsen</artist>
        <country>EU</country>
        <company>Medley</company>
        <price>7.80</price>
        <year>1983</year>
    </cd>
    <cd>
        <title>Pavarotti Gala Concert</title>
        <artist>Luciano Pavarotti</artist>
        <country>UK</country>
        <company>DECCA</company>
        <price>9.90</price>
        <year>1991</year>
    </cd>
    <cd>
        <title>The dock of the bay</title>
        <artist>Otis Redding</artist>
        <country>USA</country>
        <company>Atlantic</company>
        <price>7.90</price>
        <year>1987</year>
    </cd>
    <cd>
        <title>Picture book</title>
        <artist>Simply Red</artist>
        <country>EU</country>
        <company>Elektra</company>
        <price>7.20</price>
        <year>1985</year>
    </cd>
    <cd>
        <title>Red</title>
        <artist>The Communards</artist>
        <country>UK</country>
        <company>London</company>
        <price>7.80</price>
        <year>1987</year>
    </cd>
    <cd>
        <title>Unchain my heart</title>
        <artist>Joe Cocker</artist>
        <country>USA</country>
        <company>EMI</company>
        <price>8.20</price>
        <year>1987</year>
    </cd>
</catalog>

而且我必须遍历 xml 文档并找出第一次出现的 country = USA

<xsl:for-each select="catalog/cd[country='USA']">
      <tr>
        <td><xsl:value-of select="title"/></td>
        <td><xsl:value-of select="artist"/></td>
      </tr>
      </xsl:for-each> 

我们怎样才能从提供的条件中只得到第一行。

提前致谢

最佳答案

您可以执行以下操作:

<xsl:for-each select="catalog/cd[country='USA']">
  <xsl:if test="position() = 1">
    <tr>
      <td><xsl:value-of select="title"/></td>
      <td><xsl:value-of select="artist"/></td>
    </tr>
  </xsl:if>
</xsl:for-each>

此外，不确定它是否有效，但您可能想尝试:

<xsl:for-each select="catalog/cd[country='USA'][1]">
  <tr>
    <td><xsl:value-of select="title"/></td>
    <td><xsl:value-of select="artist"/></td>
  </tr>
</xsl:for-each>

关于xml - 遍历 xsl :for-each for 10 rows 时如何选择第一次出现的数据，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6019661/