Php 如何在mysqli查询中使用while循环

我为这个愚蠢的问题感到抱歉。我有一个这样的代码，我希望结果在while循环中完成。我以前使用过mysql，查询很简单，执行得很好。 范例

现在我使用oop，我有一个数据库类和一个连接处理程序，它被注入到从数据库类扩展而来的新类中。我的问题是在代码执行之后，我得到了这个错误方法*mysqli\u stmt:：fetch\u assoc（）*这是我的代码

<?php
class recentWorks extends DatabaseModelBase
{

public function show($tbl, $num_to_show, $site_url="") 
{

    $statement = $this->prepare('SELECT * FROM '.$tbl.' WHERE RAND()<(SELECT (( '.$num_to_show.' /COUNT(*))*10) FROM '.$tbl.' ) ORDER BY RAND() LIMIT  '.$num_to_show.'  ');
    $statement->execute();
    while ($recent_results = $statement->fetch_assoc())
    {
        $featured_work_name=$recent_results['name']; $featured_work_url=$recent_results['url']; $featured_work_thumb=$recent_results['img_thumb'];
        $featured_work_id=$recent_results['id'];$featured_work_desc=$recent_results['desc'];$featured_work_img=$recent_results['img_url'];
        ?>
  <li> 
  <a href="<?php echo $featured_work_img; ?>" class="fancybox thumb poshytip" title="Click To View Enlarged Image">
  <img src="<?php echo $featured_work_thumb; ?>" width="282px" height="150px" alt="<?php echo $featured_work_name; ?>' Image" />
  </a>
 <div class="excerpt">

 <span class="main_header"><a href="<?php echo $featured_work_url; ?>" target="_blank" class="poshytip recent-link" title="Click To Visit Website"><?php echo ucwords($featured_work_name); ?></a>
 </span>
<?php echo substr($featured_work_desc,0,300); ?>
</div>
</li>
        <?php
    }
    $statement->close();
    }

  }
 ?>

请有人帮我调试一下这个

让我们看看你以前有什么

现在让我们看看您现在有什么（选定的行）

---

$statement=$this->prepare（'SELECT*FROM.$tbl.'WHERE RAND（）谢谢你的评论和建议。但是，你有和我可以检查的链接吗？这里关于stackoverflow的大多数问题并不能解决我的问题。我编辑了问题并留下了两个链接，请随意重新加载。还可以从扩展中浏览手册页。在那里查找示例，这里有一个答案，因此无法完成与手册有。请继续阅读；）如果可以避免，请不要使用mysql_*函数，它们不再被维护，社区已经开始了弃用过程。相反，你应该学习准备好的语句，并使用PDO或MySQLi。你可能会发现它们与你的主题相关。
<?php
class recentWorks extends DatabaseModelBase
{

public function show($tbl, $num_to_show, $site_url="") 
{

    $statement = $this->prepare('SELECT * FROM '.$tbl.' WHERE RAND()<(SELECT (( '.$num_to_show.' /COUNT(*))*10) FROM '.$tbl.' ) ORDER BY RAND() LIMIT  '.$num_to_show.'  ');
    $statement->execute();
    while ($recent_results = $statement->fetch_assoc())
    {
        $featured_work_name=$recent_results['name']; $featured_work_url=$recent_results['url']; $featured_work_thumb=$recent_results['img_thumb'];
        $featured_work_id=$recent_results['id'];$featured_work_desc=$recent_results['desc'];$featured_work_img=$recent_results['img_url'];
        ?>
  <li> 
  <a href="<?php echo $featured_work_img; ?>" class="fancybox thumb poshytip" title="Click To View Enlarged Image">
  <img src="<?php echo $featured_work_thumb; ?>" width="282px" height="150px" alt="<?php echo $featured_work_name; ?>' Image" />
  </a>
 <div class="excerpt">

 <span class="main_header"><a href="<?php echo $featured_work_url; ?>" target="_blank" class="poshytip recent-link" title="Click To Visit Website"><?php echo ucwords($featured_work_name); ?></a>
 </span>
<?php echo substr($featured_work_desc,0,300); ?>
</div>
</li>
        <?php
    }
    $statement->close();
    }

  }
 ?>

$sql_query = mysql_query($query);
   `----- missing error checking and handling
while ($row = mysql_fetch_array($sql_query))
         `---- missing error handline
{
    $data_a = $row['a']; $data_b = $row['b'];
           `----- complicated way of setting variables as arrays
}

$statement = $this->prepare('SELECT * FROM '.$tbl.' WHERE RAND()<(SELECT (( '.$num_to_show.' /COUNT(*))*10) FROM '.$tbl.' ) ORDER BY RAND() LIMIT  '.$num_to_show.'  ');
                       `---- using prepare as if it would have been mysql_query()
$statement->execute();
            `----- same here