INSERT member (last, first)
VALUES(NULL, "chromatic");

##</code><code>##

$last = "NULL";
$first = "chromatic";
$query = 
qq {
	INSERT member (last, first)
	VALUES ($last, $first)
};
$rows = $dbh->do($query);

##</code><code>##

$last = $dbh->quote("NULL");
$first = $dbh->quote("chromatic");

##</code><code>##

$query = 
qq {
	INSERT member (last, first)
	VALUES (?, ?)
};
$rows = $dbh->do($query, undef, $last, $first);