Employee User Account Details 

This query returns the employee person number and the linked Oracle HCM username from the user account record. It joins the worker record with the HCM user account table and keeps only currently effective person records. Oracle documents that HCM user accounts are managed from the Manage User Account page and that usernames are created and maintained as part of HCM user account management.

SELECT
    PAPF.PERSON_NUMBER           AS Person_Number,
    PU.USERNAME                  AS User_Name
FROM
    PER_ALL_PEOPLE_F             PAPF,
    PER_USERS                    PU
WHERE
        PAPF.PERSON_ID           = PU.PERSON_ID
    AND TRUNC(SYSDATE) BETWEEN PAPF.EFFECTIVE_START_DATE AND PAPF.EFFECTIVE_END_DATE
ORDER BY
    PAPF.PERSON_NUMBER ASC,
    PU.USERNAME ASC NULLS FIRST