my @db_colnames = qw( lastname firstname middlename );

my $rs = $schema
    ->resultset('myTable')
    ->search({},
             { order_by => \@db_colnames });

for my $row ( $rs->all ) {
    my %data = $row->get_columns;
    print join("\t", @data{@db_colnames}), "\n";
}