How to remove duplicate elements from an xml file?

Question

I have an XML file like

<ns0:Employees xmlns:ns0="http://TestIndexMap.Employees">
  <Employee FirstName="FirstName_0" LastName="LastName_1" dept="dept_2" empNumber="1">
    <Schedules>
      <Schedule Date_join="2008-01-20" Date_end="2008-01-30" />
    </Schedules>
  </Employee>
  <Employee FirstName="FirstName_0" LastName="LastName_1" dept="dept_2" empNumber="2">
    <Schedules>
      <Schedule Date_join="2008-01-20" Date_end="2008-01-30" />
    </Schedules>
  </Employee>
  <Employee FirstName="FirstName_2" LastName="LastName_1" dept="dept_2" empNumber="2">
    <Schedules>
      <Schedule Date_join="2007-01-21" Date_end="2007-12-30" />

    </Schedules>
  </Employee>
  <Employee FirstName="FirstName_2" LastName="LastName_1" dept="dept_2" empNumber="2">
    <Schedules>
      <Schedule Date_join="2007-01-21" Date_end="2007-12-30" />
      <Schedule Date_join="2008-06-20" Date_end="2008-01-30" />

    </Schedules>
  </Employee>
</ns0:Employees>

I would want to remove the duplicates based on the fistname, last name and date_join and data_end .

Please, can someone explain how to achive this with XSLT?

Answer 1

Here are some samples of how to remove duplicates based on element name and id field. It should be not too hard to extend this to arbitrary fields.

Q: Expansion. A part of my xml looks like this:

 <location>
   <state>xxxx</state>
 </location>

 <location>
    <state>yyyy</state>
 </location>

  <location>
    <state>xxxx</state>
 </location>

The desired output is:

xxxx
yyyy

That is, duplicate values of state should not be printed. Can this be done?

   <xsl:variable name="unique-list"
     select="//state[not(.=following::state)]" />   

   <xsl:for-each select="$unique-list">
 <xsl:value-of select="." />
   </xsl:for-each>