Once you have the source code compiled and linked, it can be run connecting to the database specified by your ORACE_SID environment setting and using the HR/HR userID/Password. The following is an example command line with its result.
selectxpq “select XMLELEMENT("EmployeeList", XMLAGG(XMLELEMENT("Employee",
XMLATTRIBUTES( employee_id AS "EmpID"), XMLELEMENT("Name", first_name
|| ' '|| last_name), XMLELEMENT("Salary", salary))))AS result FROM
hr.employees where Salary > 13000” “//Employee/Name[../Salary="17000"]”
This query returns the following XML document from the employees table:
<EmployeeList> <Employee EmpID="100"> <Name>Steven King</Name> <Salary>24000</Salary> </Employee> <Employee EmpID="101"> <Name>Neena Kochhar</Name> <Salary>17000</Salary> </Employee> <Employee EmpID="102"> <Name>Lex De Haan</Name> <Salary>17000</Salary> </Employee> <Employee EmpID="145"> <Name>John Russell</Name> <Salary>14000</Salary> </Employee> <Employee EmpID="146"> <Name>Karen Partners</Name> <Salary>13500</Salary> </Employee> </EmployeeList>
The XPath expression //Employee/Name[../Salary="17000"] asks for all the names of employees whose salary is equal to 17000 and returns the following XML fragment:
<Name>Neena Kochhar</Name> <Name>Lex De Haan</Name>