The following code works for me. It has the following differences:

• It uses DBD::SQLite, where you use DBD::mysql
• I didn't test out putting the whole stuff into two separate files.

One thing that comes to mind: Did you install the proper Class::DBI subclass (Class::DBI::mysql) ?

Table setup script

#!/usr/bin/perl -w
use strict;
use DBI;

my $dbh = DBI->connect('dbi:SQLite:dbfile=kudra.sqlite',"","", {AutoCo
+mmit => 0});

my @statements;
{
  local $/;
  @statements = split /;/, <DATA>;
};

for my $statement (@statements) {
  print "$statement\n";
  eval {
    $dbh->do($statement);
    $dbh->commit;
  };
  $@ ||= $dbh->errstr;
  if ($@) {
    if ($statement =~ /^drop/i) {
      warn $@;
    } else {
      die $@;
    };
  };
};
$dbh->commit;
$dbh->disconnect;

__DATA__

create table person (
  id                INTEGER PRIMARY KEY,
  name              VARCHAR(256)
);

insert into person (name) values ("Corion");
insert into person (name) values ("Kudra");
insert into person (name) values ("vroom");
insert into person (name) values ("jcwren");
[download]

Class::DBI script

#!/usr/local/bin/perl -w

package MyCompany::MyProduct::Database;
use Class::DBI::Loader;
my $loader = Class::DBI::Loader->new(
    dsn           => "dbi:SQLite:dbfile=kudra.sqlite",
    user          => "username",
    password      => "password",
    namespace     => 'MyCompany::MyProduct::Database',
    relationships => 1);

package main;

use strict;
use warnings;
#use MyCompany::MyProduct::Database;
use Data::Dumper;

my $person = 
    MyCompany::MyProduct::Database::Person->retrieve(3);
print Dumper $person;
[download]