Have a look at DBIx::Simple. It's just a glue module, like yours, and already does what you appear to be looking for. It uses SQL::Abstract for query abstraction, which handles the hash case very well.

For comparison, I've translated your examples:

# DBIx::Handy
$DB->insert(table => 'customers', data => $form_data);

# DBIx::Simple
$db->insert('customers', $form_data);



# DBIx::Handy
my $href = $DB->execute(sql => $sql, method => 'fetchrow_hashref', dat
+a => \@foo);

# DBIx::Simple
my $href = $db->query($sql, @foo)->hash;



# DBIx::Handy
my $sth = $DB->execute(sql => $sql, data => \@foo);
while (my $row = $sth->fetchrow_hashref) { ... }

# DBIx::Simple
my $result = $db->query($sql, @foo);
while (my $row = $result->hash) { ... }
[download]

Note, by the way, that data from $cgi->Vars is filthy and should be carefully matched and untainted before use in databases. Even if you use placeholders. In practice, I find it easier (and a little more secure) to build a new hash (or use individual variables even).