# does not work; propably group is not supported?

use DBI;
use Fatal ':void';

open my $fh, '>', '/tmp/xyz.csv';
binmode $fh;
print $fh <<__CSV__;
aa,bb,cc
a,2,3
a,3,7
b,12,111
c,12,12
__CSV__
close $fh;

my $dbh = DBI->connect(qq{DBI:CSV:});
$dbh->{'csv_tables'}->{'t_test'} = { file => '/tmp/xyz.csv',
col_names => [qw/aa bb cc/]};

my $ar = $dbh->selectall_arrayref(
  q{                                  SELECT aa, COUNT(*) AS cnt, AVG(cc)
                                        FROM t_test
                                    GROUP BY aa
                                    ORDER BY aa  });