Query to get details for Purchase order (PO) approval History

Query to get details for Purchase order approval History 

SELECT
  pah.action_code ,
  pah.object_id ,
  pah.action_date ,
  pah.sequence_num,
  pah.creation_date ,
  prha.segment1 PO_num ,
  prha.wf_item_key ,
  prha.authorization_status ,
  fu.description ,
  papf.full_name hr_full_name ,
  papf.employee_number emp_no ,
  pj.NAME job
FROM
  po.po_action_history pah ,
  po.po_headers_all prha ,
  applsys.fnd_user fu ,
  hr.per_all_people_f papf ,
  hr.per_all_assignments_f paaf ,
  hr.per_jobs pj
WHERE
  object_id           = prha.po_header_id
AND pah.employee_id   = fu.employee_id
AND fu.employee_id    = papf.person_id
AND papf.person_id    = paaf.person_id
AND paaf.job_id       = pj.job_id
AND paaf.primary_flag = 'Y'
AND SYSDATE BETWEEN papf.effective_start_date AND papf.effective_end_date
AND SYSDATE BETWEEN paaf.effective_start_date AND paaf.effective_end_date
AND pah.object_type_code = 'PO'
AND prha.segment1        ='4010231234'
  --AND pah.action_code = 'APPROVE'
ORDER BY pah.sequence_num;

Table-types and names used in Oracle Apps

Here is a short list of the table-types and names used in Oracle Apps:

_ALL are multi-org tables.

_V are views.

_VL are views for multi language tables which combines the row of the base table with the corresponding row of the _TL table where the LANGUAGE = USERENV('LANG').
_TL are tables corresponding to another table with the same name minus the _TL. These tables provide multiple language support. For each item in the table without _TL there can be many rows in the _TL table, but all with different values in the LANGUAGE column.

_F these are date tracked tables which occur in HR and Payroll. For these there are two date columns EFFECTIVE_START_DATE and EFFECTIVE_END_DATE which together with the PK identifies a row uniquely. The date intervals cannot overlap.

_B these are the BASE tables.
They are very important and the data is stored in the these table with all validations.
It is supposed that these table will always contain the perfect format data.
If anything happens to the BASE table data, then it is a data corruption issue.

_S are sequences, used for finding new values for the primary key of a table.

_A are Audit Shadow Tables.

_AVn and _ACn are Audit Shadow Views (when data was changed, and with what values).