为什么通过php的格式不保留在一个选择框php

你好，我正在努力实现这个

http://phpfiddle.org/main/code/jw3-s1j

实际上我认为它工作得很好。但是你不能像前面的例子那样区分类别和子类别。

那么我怎么能有一个选择框与树里面??

<?PHP 
$result = mysql_query("SELECT id, parent_id, name FROM category")or trigger_error('Query failed: ' . mysql_error(), E_USER_ERROR);; // This line executes the MySQL query that you typed above
$datas = array(); // make a new array to hold all your data

while($row = mysql_fetch_assoc($result)) {
   $datas[] = $row;
}
function generatePageTree($datas, $depth = 0, $parent = 0){
    if($depth > 1000) return ''; // Make sure not to have an endless recursion
    $tree = '';
    for($i=0, $ni=count($datas); $i < $ni; $i++){
        if($datas[$i]['parent_id'] == $parent){
            $tree .= str_repeat('-', $depth);
            $tree .= '<option value='''.$datas[$i]['name'] . '''>'.$datas[$i]['name'] . '</option><br/>';
            $tree .= generatePageTree($datas, $depth+1, $datas[$i]['id']);
        }
    }
    return $tree;
}
echo '<select>';
echo(generatePageTree($datas));
echo '</select>';

?>

解决! !

固定代码:

function generatePageTree($datas, $depth = 0, $parent = 0){
    if($depth > 1000) return ''; // Make sure not to have an endless recursion
    $tree = '';
    for($i=0, $ni=count($datas); $i < $ni; $i++){
        if($datas[$i]['parent_id'] == $parent){
            $tree .= str_repeat('-', $depth);
            $tree .= '<option value='''.$datas[$i]['name'] . '''>'.str_repeat('-', $depth).$datas[$i]['name'] . '</option><br/>';
            $tree .= generatePageTree($datas, $depth+1, $datas[$i]['id']);
        }

 function generatePageTree($datas, $depth = 0, $parent = 0){
        if($depth > 1000) return ''; // Make sure not to have an endless recursion
        $tree = '';
        for($i=0, $ni=count($datas); $i < $ni; $i++){
            if($datas[$i]['parent_id'] == $parent){
                $tree .= str_repeat('-', $depth);
                $tree .= '<option value='''.$datas[$i]['name'] . '''>'.str_repeat('-', $depth).$datas[$i]['name'] . '</option><br/>';
                $tree .= generatePageTree($datas, $depth+1, $datas[$i]['id']);
            }