从Oracle表生成PL/SQL中的XML文档

DECLARE
  l_xmltype XMLTYPE;
BEGIN
  SELECT XMLELEMENT("employees",
                     XMLAGG(XMLELEMENT("employee",
                                       XMLFOREST(employee_id AS "employee_id",
                                                 first_name AS "first_name",
                                                 last_name AS "last_name",
                                                 email AS "email",
                                                 phone_number AS "phone_number"))))
    INTO l_xmltype
    FROM employees;

  DBMS_OUTPUT.PUT_LINE(l_xmltype.getClobVal());
END;