That way I can +1 in my perlish ways to help complete my current script

This suspiciously sounds as if you're trying to manually create a primary key for your table. That's bad because if your script runs twice at the same time, you can get the same number twice:

# Two scripts in parallel:
my $highest_id1 = $dbh->do("select max(id) from my_table"); # first sc
+ript
my $highest_id2 = $dbh->do("select max(id) from my_table"); # second s
+cript

$highest_id1++; # first script
$highest_id2++; # second script

if ($highest_id1 == $highest_id2) {
    die
};
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What you want is a primary key on your table. In most SQL databases, you can do that with:

create table my_table (
    id integer primary key not null,
    ....
);

-- or
create unique index idx_id on my_table (id);

-- or, in MySQL I think:
create table my_table (
    id integer not null auto_increment,
    ....
);
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Also read the DBI documentation on retrieving the last insert id.

my $dbh = DBI->connect(...);
my($max_foo) = $dbh->selectrow_array(q{
    SELECT MAX(foo) FROM bar
});
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Does "SELECT something something ORDER BY something.id DESC LIMIT 1" help? if not, please be clearer.

SELECT MAX(id) FROM tablename
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