从php表中查询结果填充下拉列表

Question

我一直在试图填充下拉列表中的结果从一个查询使用PHP从一个MySQL表，但列表是空的。有人可以看看我的代码，告诉我我做错了什么。

我的查询是Select cat from kernel

我使用的代码：$results = $query->fetchAll();

继承人我的代码：

<?php 

$dbhandle = new PDO('host','username','password'); 


$sql = "SELECT cat FROM kernel"; 
$results = $query->fetchAll(); 

echo "<select name='cat'>"; 
while ($row = mysql_fetch_array($result)) { 
echo "<option value='" . $row['cat'] . "'>" . $row['cat'] . "</option>"; 
} 
echo "</select>"; 

?> 

Answer 1

<?php 

$sth = $dbhandle->prepare("SELECT cat FROM kernel"); 
$sth->execute(); 
$results = $sth->fetchAll(PDO::FETCH_ASSOC); 

echo "<select name='cat'>"; 
foreach($results as $row) { 
    echo "<option value='" . $row['cat'] . "'>" . $row['cat'] . "</option>"; 
}  
echo "</select>"; 

?> 

http://us2.php.net/manual/en/pdostatement.fetchall.php