use strict;
use warnings;
use DBI;
my $dbh = DBI->connect("DBI:mysql:test", '*', '*') or die("booh");
my $sth = $dbh->prepare("select value from s") or die ("looh");
$sth->execute() or die("hoo");
while (my @array = $sth->fetchrow_array()) {
  defined($_) ? print "$_\n" : die "\$_ is undef\n";
}
__END__
$_ is undef