php - 更新表 php-mysql 中的值

Question

我有这张表:

+----+------------+-----------------------+
| ID | ID_PRODUCT | LINK_DOWNLOAD         |
+----+------------+-----------------------+
| 1  |  2369      | folder/2015.03.12.pdf |
| 2  |  3694      | folder/2014.01.10.pdf |
| 3  |    56      | folder/2016.09.25.pdf |
+----+------------+-----------------------+

结束代码 php:

  <form action="upload_file.php" method="post" enctype="multipart/form-data" name="upload_file"><br>
    <label for="UploadFileField"></label><br>
    <input type="file" name="UploadFileField"/>
    <input type="submit" name="UploadButton" value="Upload" /><br>
    <input type ="text" name="UPLOAD_COD" />
  </form>


<?php
include "bd_cnx.php";
if (isset ($_FILES['UploadFileField'])){
  $UploadName = $_FILES['UploadFileField'] ['name'];
  $UploadName = mt_rand (100000, 999999).$UploadName;
  $UploadTmp = $_FILES['UploadFileField'] ['tmp_name'];
  $UploadType = $_FILES['UploadFileField'] ['type'];
  $FileSize = $_FILES['UploadFileField'] ['size'];

  $UploadName = preg_replace("#[^a-z0-9.]#i", "", $UploadName);

  if(($FileSize > 1250000)){
    die ("Error - File to big");
  }

  if(!$UploadTmp) {
    die ("No File Selected");
  }
  else {
    if (move_uploaded_file($UploadTmp, "Upload/$UploadName")) {
            $UPLOAD_COD = $_POST['UPLOAD_COD'];
            $sql = "INSERT INTO download (ID_PRODUCT,LINK_DOWNLOAD) VALUES ('$UPLOAD_COD','Upload/$UploadName')";
            $result = $conn->query($sql);
        echo '<script> alert("Successfully inserted"); window.location ="/index.php";</script>';
    }
  }
}
 ?>

2015.03.12.pdf 文件今天更新并成为 2016.09.25.pdf 。当我在输入“UPLOAD_COD”中输入数字 2369 时，我想从服务器中删除文件 2015.03.12.pdf 并替换为 2016.09.25.pdf，并在 LINK_DOWNLOAD 列中更新到新链接(文件夹/2015.03.12.pdf)。谢谢!

Answer 1

所以你想删除 ID_PRODUCT = 2369 的文件？只需从数据库中获取 LINK_DOWNLOAD

上传并插入文件后放置此代码

//first create a query that select the row of the data that you are finding
$currentSql = "Select * from download where ID_PRODUCT = '".$UPLOAD_COD."'";
$current = $conn->query($currentSql);


// then fetch it's result then unlink the file from the server
while($row = $current->fetch_assoc()) {
    $file = $row['LINK_DOWNLOAD'];
    // check if file is exist then delete
    if (file_exists($file)) {
        unlink($file);
    }
}