thinkphp中怎么办上传文件

thinkphp中怎么处理上传文件
thinkphp中怎么处理上传文件，也即要处理所有文件。自己做了一个网站要上传所有的文件 包括图片、txt、doc、视频等等。如何上传 插入数据库里面呀？
$m = M("file");
//$_clean = array();
if (!empty($_FILES)){
$im = $this->_upload();
$_POST["filename"] = $im;
$_POST["uptime"] = time();

}

$n = $m->add();
if ($n){
$str = "添加成功";
}else {
$str = "添加失败";
}
$this->assign("str",$str);
$this->display("upload");
}

// 文件上传
protected function _upload() {
import("@.ORG.UploadFile");
$upload = new UploadFile();
//设置上传文件大小
$upload->maxSize = 3292200;
//设置上传文件类型
$upload->allowExts = explode(',', 'jpg,gif,png,jpeg,pjpeg,bmp,doc,rar,txt');
//设置附件上传目录
$upload->savePath = './Public/upload/';
//设置上传文件规则
$upload->saveRule = uniqid;
if (!$upload->upload()) {
//捕获上传异常
$this->error($upload->getErrorMsg());
} else {
//取得成功上传的文件信息
$uploadList = $upload->getUploadFileInfo();
//import("@.ORG.Image");
//给m_缩略图添加水印, Image::water('原文件名','水印图片地址')
/*Image::water($uploadList[0]['savepath'].'m_'.$uploadList[0]['savename'], '/ThinkPHP_2.1_full_with_extend/Examples/File/Tpl/default/Public/Images/logo2.png'); */
return $uploadList[0]['savename'];
}

} 我这样处理不行哦。

------解决方案--------------------
http://thinkphp.cn/Manual/170
------解决方案--------------------
thinkphp不是有demo吗？
------解决方案--------------------
$upload->savePath = './Public/upload/';
改成
$upload->savePath = './upload/';
你试一试