my ($result_ref, $columnNames_ref, $numFields)  = fetchRowArray($dbh, $sql);
... 
sub fetchRowArray($$){
  my $dbh = shift;
  my $sql = shift;
  my $sth = $dbh->prepare($sql) or meldeFehler("Statement could not prepared");
  $sth->execute() or meldeFehler("Statement could not executed"); 
  my $columnNames;
  $columnNames = $sth->{NAME}; 
  my $numfields;
  $numfields = $sth->{NUM_OF_FIELDS};
  my (@matrix) = ();
  while (my @ary = $sth->fetchrow_array())
    {
      push(@matrix, [@ary]); 
    }
  $sth->finish();
  return \@matrix, $columnNames, $numfields; 
 
}