Convert ->numrows for use with DBD::mysql in Perl

Question

I have some old code that uses the old Mysql library in Perl.

Most of the time updating the code to use DBD::mysql instead works with no problems however I have run into an issue where ->numrows does not work.

What should I do to get the same functionality whilst using DBD::mysql

use Mysql

use Mysql;

$type = "yellow";

$statement = "select name from customer where type = '$type'";

$sth = $dbh->query($statement);

if ($sth->numrows) {
  print "Success!"; # This does work.
}

use DBD::mysql

use DBI;
use DBD::mysql;

$type = "yellow";

$statement = "select name from customer where type = ?";

$sth = $dbh->prepare($statement);
$sth->execute($type);

if ($sth->numrows) {
  print "Success!"; # This doesn't work.
}

This is the error I get back:

tail /var/log/apache2/error.log

 Can't locate object method "numrows" via package "DBI::st"

Answer 1

我认为你应该使用它如下

if ($sth->rows)