php 上传文件条件不工作

Question

我有一个访问者可以上传文件的页面，但这不是必需的，所以在我的脚本中我设置了一个条件，如果文件输入（我将其命名为 'upload'）未设置或为空不要上传任何东西，文件名将等于 'file' 已存在于数据库中；否则上传它。问题是条件不工作；即使我将输入留空，也会执行上传脚本；我知道是因为我收到了脚本中声明的消息这是编码，谢谢

    //select exercice
$ex_query = mysqli_query($link, " SELECT * FROM exercices WHERE ID = '".$exercice_ID."' ");
$exercice = mysqli_fetch_assoc($ex_query);
// --- update script if post
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    if (isset($_FILES["upload"]) && !empty($_FILES["upload"])){
        $target_dir = "docs/";
        $date_f_n = date("Y-m-d_h-i-sa");
        $file_n = basename( $_FILES["upload"]["name"]);
        $file_n = $date_f_n.$file_n;
        $target_file = $target_dir . $file_n;
        $uploadOk = 1;
        $FileType = pathinfo($target_file,PATHINFO_EXTENSION);
        // Check if  file is a actual image or fake image
            $check = filesize($_FILES["upload"]["tmp_name"]);
            if($check !== false) {
                $uploadOk = 1;
            } else {
                $filesizeer = "File is not an image.";
                $uploadOk = 0;
            }
         // Check file size
        if ($_FILES["upload"]["size"] > 5000000) {
            $filesizeer = "Sorry, your file is too large.";
            $uploadOk = 0;
        }
        // Check if $uploadOk is set to 0 by an error
        if ($uploadOk == 0) {
            $error = "Sorry, your file was not uploaded.";
        // if everything is ok, try to upload file
        } else {
             if (move_uploaded_file($_FILES["upload"]["tmp_name"], $target_file)) {
            $upsuccess= "The file ". $file_n. " has been uploaded.";
            } else {
                $upfaled =  "Sorry, there was an error uploading your file.";
            }
        }//end else upload = 0
    }else{
        $file_n = $exercice['file'];
    }

Answer 1

第一个 上传必须做的事情是检查上传是否完全执行，以及上传是否成功。 $_FILES['foo'] 存在并不意味着 foo 文件上传成功。

最低限度检查：

if ($_FILES['foo']['error'] !== UPLOAD_ERR_OK) {
   die("Upload failed with error code #" . $_FILES['foo']['error']);
}

甚至

if (isset($_FILES['foo']) && etc...)

如果你想严格正确的话。

如果您想允许非上传，但仍然因实际错误而失败，请检查您希望允许的特定错误代码 "ok"。错误代码在此处定义：http://php.net/manual/en/features.file-upload.errors.php

php 上传文件条件不工作

php upload file condition not working

php

file-upload