“Update the Prices in a Database!”
use DBI;
$db = DBI->connect('dbi:ODBC:PRICE', 'user', 'password',
     { RaiseError => 1 });
$upd = $db->prepare('UPDATE prices SET price=? WHERE prod=?');
$ins = $db->prepare('INSERT INTO prices(prod,price) VALUES (?,?)');
while ($line = <COST>) {
    . . .
    $rows = $upd->execute($price, $prod);
    $ins->execute($prod,$price) if $rows == 0;
}
$db->commit;
13