my $sth = $dbh->prepare ("select a1, a2, a3, a4 from tbl");
   $sth->execute;
my %rec;
$sth->bind_columns (\@rec{my @fld = @{$sth->{NAME_lc}});
while ($sth->fetch) {
    say "Column a1: $rec{a1}";
    }