查詢丟失的PO號碼

SELECT org_id,
    segment1,
    next_segment1,
    next_segment1 - segment1 - 1 missing
 FROM (SELECT org_id,
        segment1,
        LEAD(segment1) OVER(ORDER BY segment1) next_segment1
     FROM po.po_headers_all)
 WHERE segment1 <> next_segment1 - 1