script to show item number

Dear all,

I would like to get the records of procurement with detail item number and description for each PO Line.

i try with script, but the item number not shown can any one asisst me ?

SELECT
poh.po_header_id,
poh.creation_date PO_Date,
poh.segment1 po_number,
poh.comments description,
poh.vendor_id,
pol.line_num,
pol.item_id,
inv.item_number Item_Number,
pol.item_description,
pol.uom_code UOM,
pol.unit_price,
pol.quantity
FROM
po_headers_all poh
JOIN po_lines_all pol ON poh.po_header_id = pol.po_header_id
JOIN po_distributions_all pod ON pol.po_line_id = pod.po_line_id