UpdateXML : How to update EmployeeName tag based on EmployeeID value

Question

Hi All,
My XMLType (EMP_DOCUMENT) field in a table stores the following simple XML structure:
<DEPARTMENT>
     <DEPARTMENT_ID>1</DEPARTMENT_ID>
     <DEPARTMENT_NAME>Finance</DEPARTMENT_NAME>
     <EMPLOYEE>
          <EMPLOYEE_ID>1</EMPLOYEE_ID>
          <FIRST_NAME>ABC</FIRST_NAME>
          <EMAIL>ABC</EMAIL>
</EMPLOYEE>
     <EMPLOYEE>
          <EMPLOYEE_ID>2</EMPLOYEE_ID>
          <FIRST_NAME>xyz</FIRST_NAME>
          <EMAIL>xyz</EMAIL>
</EMPLOYEE>
     <EMPLOYEE>
          <EMPLOYEE_ID>3</EMPLOYEE_ID>
          <FIRST_NAME>zzzz</FIRST_NAME>
          <EMAIL>zzz</EMAIL>
</EMPLOYEE>
     <EMPLOYEE>
          <EMPLOYEE_ID>4</EMPLOYEE_ID>
          <FIRST_NAME>yyyy</FIRST_NAME>
          <EMAIL>yyyy</EMAIL>
</EMPLOYEE>
</DEPARTMENT>
Employee_ID is unique and Employee_Name is not unique.
I have a requirement to update the Employee_Name tag where i have the Employee_ID and the value to be updated.I tried the following but it updates all Employee_Names instead of updating the record i want:
UPDATE EMPLOYEE_DOCUMENTS p
SET p.EMP_DOCUMENT = updateXML(p.EMP_DOCUMENT,
               '/DEPARTMENT/EMPLOYEE/FIRST_NAME/text()',
          'Scott')
WHERE DOCUMENT_ID = 1
AND existsNode(p.EMP_DOCUMENT,'/DEPARTMENT/EMPLOYEE[EMPLOYEE_ID = 2')=1
I can see that updateXML essentially acts as 'ReplaceXML' where one tag can be searched and replaced with the new value.But is it possible to UPDATE a tag based on other tag at the same level (like update the employee_name based on employee_id)
Thanks,
Srihari
Edited by: srihari manian on Jul 15, 2009 7:19 AM                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

Answer 1

I believe this is what you are looking for
WITH employee_documents AS
(SELECT XMLTYPE('<DEPARTMENT>
<DEPARTMENT_ID>1</DEPARTMENT_ID>
<DEPARTMENT_NAME>Finance</DEPARTMENT_NAME>
<EMPLOYEE>
<EMPLOYEE_ID>1</EMPLOYEE_ID>
<FIRST_NAME>ABC</FIRST_NAME>
<EMAIL>ABC</EMAIL>
</EMPLOYEE>
<EMPLOYEE>
<EMPLOYEE_ID>2</EMPLOYEE_ID>
<FIRST_NAME>xyz</FIRST_NAME>
<EMAIL>xyz</EMAIL>
</EMPLOYEE>
<EMPLOYEE>
<EMPLOYEE_ID>3</EMPLOYEE_ID>
<FIRST_NAME>zzzz</FIRST_NAME>
<EMAIL>zzz</EMAIL>
</EMPLOYEE>
<EMPLOYEE>
<EMPLOYEE_ID>4</EMPLOYEE_ID>
<FIRST_NAME>yyyy</FIRST_NAME>
<EMAIL>yyyy</EMAIL>
</EMPLOYEE>
</DEPARTMENT>') emp_document
  FROM DUAL
SELECT updateXML(p.EMP_DOCUMENT,
'/DEPARTMENT/EMPLOYEE[EMPLOYEE_ID = 2]/FIRST_NAME/text()',
'Scott')
  FROM employee_documents pwhich just updates the name for employee id 2.