use Modern::Perl qw/2014/;
use DBI;

my $dbh = DBI->connect("dbi:CSV:");

my $query =
"SELECT col1, count(col1) AS counter FROM test.csv WHERE  col5 = 'yes' GROUP by col1 ORDER BY col1";
my $sth = $dbh->prepare($query);
$sth->execute();
while ( my $row = $sth->fetchrow_hashref ) {
    say $row->{col1}, "\t", $row->{'counter'};
}