SELECT inv_no, NVL2(inv_date, 'Pending', 'Incomplete') FROM invoice;
SELECT inv_no, NVL2(inv_amt, inv_date, 'Not Available') FROM invoice;
SELECT inv_no, NVL2(inv_date, sysdate-inv_date, sysdate) FROM invoice;
SELECT inv_no, NVL2(inv_amt, inv_amt*.25, 'Not Available') FROM invoice;