Re: foreign keys in a xml-database, how to copy a node

The PROBLEM is, that the above construction copies each tool

> with all its childs ( releases ) from second.xml and not only
> those, whose @name fits @version of the corresponding tool from first xml.

Match the release and copy stuff from the parent (the tool) as
needed:
 <xsl:key name="tool-release" match="release"
   use="concat(../@name,'#',@name)"/>
...

   <xsl:variable name="tools">
     <xsl:for-each select="tool">
      <xsl:variable name="key" select="concat(@name,'#',@version)"/>
      <xsl:for-each select="$sw-file">
        <xsl:variable name="release" select="key('tool-release',$key)"/>
        <tool>
          <xsl:copy-of select="$release/../@*"/>
          <xsl:copy-of select="$release/../*[not(self:release)]"/>
          <xsl:copy-of select="$release"/>
        </tool>
      </xsl:for-each>
     </xsl:for-each>
    </xsl:variable>