PHP printf(）函数不输出任何内容

我的代码运行时没有错误，但当我需要一些输出时，不会产生任何输出。

这是代码：

<?php
   $result = mysqli_query ($link, "SELECT * FROM `tickets`");
   while ($myrow = mysqli_fetch_assoc ($result));
   {
   printf ("<tr>
       <td><a href='/admin/ticket.php?ticket=%s'>%s</a></td>
       <td>%s</td><td>%s</td>
       <td>%s</td><td>%s</td>
       <td>%s</td><td>%s</td>
       <td>%s</td><td>%s</td>
       <td>%s</td><td>%s</td>
       <td><a href='/admin/history.php?id=%s'><img src='/admin/img/doc.png' alt=''></a></td></tr>",
       $myrow['id'],
       $myrow['id'],
       $myrow['sla'],
       $myrow['category'],
       $myrow['date'],
       $myrow['time'],
       $myrow['vendor'],
       $myrow['mark'],
       $myrow['model'],
       $myrow['status'],
       $myrow['description'],
       $myrow['modified'],
       $myrow['id']);
   }
?>

你能告诉我，我在什么地方搞砸了吗？查询返回非空结果，数据库中的数据可用，字段名称正确，连接正确。。。这是数据库结构：

   CREATE TABLE IF NOT EXISTS `tickets` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `number` varchar(10) DEFAULT NULL,
  `sla` varchar(10) NOT NULL,
  `category` varchar(20) NOT NULL,
  `date` date NOT NULL,
  `time` time NOT NULL,
  `modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `vendor` varchar(50) NOT NULL,
  `mark` varchar(50) NOT NULL,
  `model` varchar(50) NOT NULL,
  `status` varchar(50) NOT NULL,
  `description` text NOT NULL,
  `timespent` varchar(50) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=18 ;