MERGE INTO 
    rlarp.customer_review w
USING 
    ( SELECT $1 bill_cust, $2 ship_cust, $3::numeric expected, $4 expecteduom) as i ON
        i.ship_cust = w.ship_cust
        AND i.bill_cust = w.bill_cust
WHEN MATCHED THEN UPDATE SET 
    newords = i.expected
    ,newuom = i.expecteduom
WHEN NOT MATCHED THEN 
    INSERT (bill_cust, ship_cust, newords, newuom)
    VALUES (bill_cust,i.ship_cust, i.expected, i.expecteduom)