perl select count(*) 返回0条,为假判断

#!/usr/bin/perl 
use strict;
use DBI;
my $dbName = 'orcl';
my $dbUser = 'test';
my $dbUserPass = 'test';
my $dbh = DBI->connect("dbi:Oracle:$dbName", $dbUser, $dbUserPass) or die "can't connect to database " ;
my $sql = "select count(*) from a11";
print "$sql is $sql..
";
my $sth = $dbh->prepare($sql);
print "$sth is $sth..
";

$sth->execute();
my $count = $sth->fetchrow_array();
print "$count is $count....
";
if ( $count  ){
print "not empty";}
else {print "empty
"}
$sth->finish;

$dbh->disconnect;
[oracle@jhoa ~]$ perl dbi.pl 
$sql is select count(*) from a11..
$sth is DBI::st=HASH(0x2df1db0)..
$count is 0....
empty


0在perl里为假:
[oracle@jhoa ~]$ cat a2.pl 
my $count = 0;
if ( $count  ){
print "not empty
";}
else {print "empty
"}

[oracle@jhoa ~]$ perl a2.pl 
empty

[oracle@jhoa ~]$ cat a2.pl 
my $count = 2;
if ( $count  ){
print "not empty
";}
else {print "empty
"}

[oracle@jhoa ~]$ perl a2.pl 
not empty