Question

I need to pull data out of XML in some specific way using XPATH and XSLT

<data>      
    <person id="p1">         
        <name>User1</name>      
    </person>   
    <person id="p2">         
        <name>User2</name>      
    </person>  
    <person id="p3">         
        <name>User3</name>      
    </person>       
    <employee eid="emp1" pid="p1">         
        <dept>dept1</dept>      
    </employee> 
    <employee eid="emp2" pid="p3">         
        <dept>dept3</dept>      
    </employee>
    <employee eid="emp3" pid="p2">         
        <dept>dept1</dept>      
    </employee>
</data>

From the above example I need to create XMLs of each with the Person and the corresponding Employee elements in the output xml. The link between these two xmls is

person.id = employee.pid

like
XML1:

<person id="p1">         
<name>User1</name>      
</person>  
<employee eid="emp1" pid="p1">         
<dept>dept1</dept>      
</employee>

XML2:

<person id="p2">         
<name>User2</name>      
</person> 
<employee eid="emp3" pid="p2">         
 <dept>dept1</dept>      
</employee>

XML3:

<person id="p3">         
<name>User3</name>      
</person> 
<employee eid="emp2" pid="p3">         
<dept>dept3</dept>      
</employee>  

I have tried many ways but not able to get this.

Thanks…

Answer 1

XPath is a query language for XML documents — as such the evaluation of an XPath expression cannot modify an existing document or create a new XML document.

What you want can best be achieved using XSLT 2.0 (XSLT 1.0 if only one result document is needed):

<xsl:stylesheet version="2.0"   xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output omit-xml-declaration="yes" indent="yes"/>
    <xsl:strip-space elements="*"/>

    <xsl:key name="kEmpByPid" match="employee" use="@pid"/>

 <xsl:template match="person">
  <xsl:result-document href="file:///c:/temp/delete/XML{position()}">
      <t>
             <xsl:copy-of select=".|key('kEmpByPid', @id)"/>
         </t>
     </xsl:result-document>
 </xsl:template>
 <xsl:template match="text()"/>
</xsl:stylesheet>

When this XSLT 2.0 transformation is applied on the provided XML document:

<data>
    <person id="p1">
        <name>User1</name>
    </person>
    <person id="p2">
        <name>User2</name>
    </person>
    <person id="p3">
        <name>User3</name>
    </person>
    <employee eid="emp1" pid="p1">
        <dept>dept1</dept>
    </employee>
    <employee eid="emp2" pid="p3">
        <dept>dept3</dept>
    </employee>
    <employee eid="emp3" pid="p2">
        <dept>dept1</dept>
    </employee>
</data>

the following three XML documents are created in “c:\temp\delete”:

XML1:

<t>
   <person id="p1">
      <name>User1</name>
   </person>
   <employee eid="emp1" pid="p1">
      <dept>dept1</dept>
   </employee>
</t>

XML2:

<t>
   <person id="p2">
      <name>User2</name>
   </person>
   <employee eid="emp3" pid="p2">
      <dept>dept1</dept>
   </employee>
</t>

XML3:

<t>
   <person id="p3">
      <name>User3</name>
   </person>
   <employee eid="emp2" pid="p3">
      <dept>dept3</dept>
   </employee>
</t>