PHP 无限极分类下拉列表实现

1. 递归实现下拉列表

/**
 * @param 递归 实现下拉列表 分类
 */

include('db.inc.php');

function getList($pid = 0,&$result = array(), $spac = 0){
    $spac = $spac + 2;
    $sql = "SELECT * FROM DEEPCATE WHERE pid = $pid";
    $res = mysql_query($sql);
    while($row = mysql_fetch_array($res)){
        $row['catename'] = str_repeat(' ',$spac).'|--'.$row['catename'];
        $result[] = $row;
        getList($row['id'],$result,$spac);
    }
    return $result;
}

function displayCate($pid=0,$select = 0){
    $rs = getList($pid);
    $str .= "<select name = 'cate'>";
    foreach ($rs as $key => $val) {
        $selected = '';
        if($val['id'] == $selected){
            $selected = "selected";
        }
        $str .= "<option {$selected}>{$val['catename']}</option>";
    }
    return $str .= '</select>'
}

echo displayCate(0);