Step 1: Specify the source and target databases using Class::DBI

Legacy database Class::DBI:

package Legacy::DBI;
use base 'Class::DBI';

__PACKAGE__->connection('dbi:mysql:legacy_games', 'user', 'password');

package Legacy::DBI::Game;
use base 'Legacy::DBI';

__PACKAGE__->table('games');
__PACKAGE__->columns(All => qw/game_id game_name game_keywords game_url/);