xlst transformation to display departments of each company node - xslt

Question

I am beginner for XSLT, currently I am trying to display list of <department> in each <company> node.
Below is my XML
<employee_data>
<employeedetails id="1">
<company id="1">
<companyname>AOL</companyname>
<department>IT</department>
</company>
<employeename>Patrick</employeename>
<employeedesg>Software Engineer</employeedesg>
<employeesalary>18000</employeesalary>
<employeedoj>10/03/2015</employeedoj>
</employeedetails>
..... similar sets......
..... similar sets......
<employeedetails id="10">
<company id="1">
<companyname>AOL</companyname>
<department>HR</department>
</company>
<employeename>Patricia</employeename>
<employeedesg>HR Assistant</employeedesg>
<employeesalary>18000</employeesalary>
<employeedoj>10/03/2015</employeedoj>
</employeedetails>
</employee_data>
I have written the below XSLT to fetch only company names, but I want to display all the departments from the various companies.
XSLT:
<xsl:key name="companyname" match="/employee_data/employeedetails/company/companyname" use="."/>
<xsl:for-each select="/employee_data/employeedetails/company/companyname[generate-id() = generate-id(key('companyname',.)[1])]">
<tr>
<td>
<xsl:value-of select="../#id"/>
</td>
<td>
<xsl:value-of select="."/>
</td>
</tr>
</xsl:for-each>

Answer 1

If you want to get the department nodes for a company simply use the same key that you have used in the grouping of the companies
<xsl:for-each select="key('companyname',.)">
<xsl:value-of select="../department" />
<br />
</xsl:for-each>
As a side note, you can actually simplify your key. You don't actually need to specify the full path to the company element, just the name will do
<xsl:key name="companyname" match="company" use="companyname"/>
You would only need to consider using a path if there were other company elements at a different level in the XML hierarchy that you didn't want included.
Also note I am matching company and not companyname simply to avoid using the .. parent axis.
Try this XSLT
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="html" />
<xsl:key name="companyname" match="company" use="companyname"/>
<xsl:template match="/">
<xsl:for-each select="/employee_data/employeedetails/company[generate-id() = generate-id(key('companyname', companyname)[1])]">
<tr>
<td>
<xsl:value-of select="#id"/>
</td>
<td>
<xsl:apply-templates select="key('companyname', companyname)" />
</td>
</tr>
</xsl:for-each>
</xsl:template>
<xsl:template match="company">
<xsl:value-of select="department" />
<br />
</xsl:template>
</xsl:stylesheet>