title: fetchrow_hashref issue in perl
body: <p>I am not able to retrieve the output properly using the below code. Please help me to sort it out.</p>
  
  <p>I am getting output differently to run in MySQL and Perl.</p>
  
  <p>As of now it is returning undef when I use Dumper. But I want it to display null.</p>
  
  <pre><code>    $reactivate_sth = $dbh-&gt;prepare("
        SELECT
          a,
          b
        FROM
          table
        WHERE
          c = ?
        AND
          d = ?
        ORDER BY
          date DESC
      ");
  $reactivate_sth-&gt;execute($c, $d);
  print $result = $reactivate_sth-&gt;fetchrow_hashref();
  </code></pre>
  
  <p>OUTPUT:</p>
  
  <p>MySQL:</p>
  
  <pre><code>Empty set (0.00 sec)
  </code></pre>
  
  <p>Perl:</p>
  
  <pre><code>HASH(0x3068198)
  </code></pre>
  
  <p>Data::Dumper</p>
  
  <pre><code>VAR1 = undef
  </code></pre>