my $sth = $dbh->prepare("UPDATE $table SET upc=$upc WHERE item_id=$item_id;");
die "DBH Error:" . $dbh->errstr . "\n" if (!$sth);
if (!$sth->execute) {
	# Oops!  $item_id doesn't exist in $table so add it.
	my $sth = $dbh->prepare("INSERT INTO $table (item_id, upc) VALUES($item_id, $upc);");
	die "DBH Error:" . $dbh->errstr . "\n" if (!$sth);
	die "STH Error:" . $sth->errstr . "\n" if (!$sth->execute);
}