相关疑难解决方法(0)

我有一个XML文件

<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>

我想根据fistname,姓氏和date_join以及data_end删除重复项.

请问,有人可以解释如何使用XSLT实现这一目标吗？