UPDATE sale
INNER JOIN (
SELECT
sale.FNo,
sale.FEntryID,
(finishin.FQty) AS qty
FROM
sale,
finishin
WHERE
sale.FNo = finishin.FNo
AND sale.FEntryID = finishin.FEntryID
ORDER BY
sale.FNo
) sale2 ON sale2.FNo = sale.FNo
AND sale2.FEntryID = sale.FEntryID
SET sale.FqtyIn = sale2.qty