压缩多个数据库PDF blob文件 [英] Zip multiple database PDF blob files

问题描述

我有一个数据库表，其中包含大量的PDF blob文件。我尝试将所有文​​件合并到一个ZIP文件，我可以下载然后打印。

请帮助！

 <？php 
 include'../config.php'; 
 include'../connect.php'; 
 
 $ session = $ _GET ['session']; 
 
 $ query =SELECT $ tbl_uploads.username，$ tbl_uploads.description，
 $ tbl_uploads.type，$ tbl_uploads.size，$ tbl_uploads.content，
 $ tbl_members.session 
 FROM $ tbl_uploads 
 LEFT JOIN $ tbl_members 
 ON $ tbl_uploads.username = $ tbl_members.username 
 WHERE $ tbl_members.session ='$ session'; 
 $ result = mysql_query（$ query）或die（'Error，query failed'）; 
 
 
 $ files = array（）; 
 while（list（$ username，$ description，$ type，$ size，$ content）= 
 mysql_fetch_array（$ result））{
 
 $ files [] =$ username- $ description.pdf; 
} 
 
 $ zip = new ZipArchive; 
 $ zip-> open（'file.zip'，ZipArchive :: CREATE）; 
 foreach（$ files as $ file）{
 $ zip-> addFile（$ file）; 
} 
 $ zip-> close（）; 
 
 header（'Content-Type：application / zip'）; 
 header（'Content-disposition：attachment; filename = filename.zip'）; 
 header（'Content-Length：'。filesize（$ zipfilename））; 
 readfile（$ zipname）; 
 
 exit（）; 
 
 
？> 
  

解决方案

您的PDF数据存储在BLOB字段的数据库，我看不到你把这个数据放在一个文件。因此，您的ZIP不会包含任何文件，因为您不向其中添加真实的现有文件。

这是您当前正在做的：

• 从数据库读取数据


• 创建文件名数组


• 创建可能不存在的文件名的ZIP

您应该这样做：

• 从数据库读取数据


• 创建文件名数组


• 将BLOB数据写入该文件
• 
  
• 创建现有文件的ZIP

示例：

  $ files = array（）; 
 while（list（$ username，$ description，$ type，$ size，$ content）= 
 mysql_fetch_array（$ result））{
 $ files [] =$ username- $ description .pdf; 
 
 //将BLOB内容写入文件
 if（file_put_contents（$ username- $ description.pdf，$ content）=== FALSE）{
 echo无法写PDF文件; 
} 
} 
  

你应该怎么办： / p>

将文件写入临时文件夹（也许有一些帮助 http ：//php.net/tempnam ）在其他地方，可能会在您的存档过程后删除它们。

在您的代码中还有第二个问题，使用$ zipfilename计算内容长度和$ zipname读取文件，没有变量创建zip。由于$ zipfilename和$ zipname没有定义，这将不起作用。

你应该用ZIP文件名定义$ zipfilename，并且在创建zip时使用同一个变量文件

示例：

  current unix timestamp 
 $ zipfilename ='temp_'。时间（） 。 '。压缩'; 
 
 $ zip-> open（$ zipfilename，ZipArchive :: CREATE）; 
 foreach（$ files as $ file）{
 $ zip-> addFile（$ file）; 
} 
 $ zip-> close（）; 
 
 header（'Content-Type：application / zip'）; 
 header（'Content-disposition：attachment; filename = filename.zip'）; 
 header（'Content-Length：'。filesize（$ zipfilename））; 
 readfile（$ zipfilename）; 
  

I have a database table that contains numerous PDF blob files. I am attempting to combine all of the files into a single ZIP file that I can download and then print.

Please help!

<?php 
    include '../config.php';
    include '../connect.php';

    $session = $_GET['session'];

    $query = "SELECT $tbl_uploads.username, $tbl_uploads.description,
                     $tbl_uploads.type, $tbl_uploads.size, $tbl_uploads.content,
                     $tbl_members.session
    FROM $tbl_uploads
    LEFT JOIN $tbl_members
    ON $tbl_uploads.username = $tbl_members.username
    WHERE $tbl_members.session = '$session'";
    $result = mysql_query($query) or die('Error, query failed');


    $files = array();
    while(list($username, $description, $type, $size, $content) = 
     mysql_fetch_array($result)) {

        $files[] = "$username-$description.pdf";
    }

    $zip = new ZipArchive; 
    $zip->open('file.zip', ZipArchive::CREATE); 
    foreach ($files as $file) { 
      $zip->addFile($file); 
    } 
    $zip->close(); 

    header('Content-Type: application/zip'); 
    header('Content-disposition: attachment; filename=filename.zip'); 
    header('Content-Length: ' . filesize($zipfilename)); 
    readfile($zipname); 

    exit();


    ?>

解决方案

Your PDF data is stored in the database in BLOB fields, I don't see you putting this data in a file. So your ZIP will not contain any files because you don't add real existing files to it.

This is what you are currently doing:

• Reading your data from the database
• Creating an array of filenames
• Creating a ZIP of filenames that might not exist

This what you should do:

• Reading your data from the database
• Creating an array of filenames
• Write your BLOB data into that files
• Creating a ZIP of files that exist

Example:

    $files = array();
    while(list($username, $description, $type, $size, $content) = 
     mysql_fetch_array($result)) {
        $files[] = "$username-$description.pdf";

        // write the BLOB Content to the file
        if ( file_put_contents("$username-$description.pdf", $content) === FALSE ) {
          echo "Could not write PDF File";
        }
    }

What you should do if that works for you:

Write the files in a temporary folder (maybe with some help of http://php.net/tempnam) somewhere else and maybe remove them after your archiving process.

There is also a second problem in your code, you use $zipfilename for calculating the content-length and $zipname to read the file and no variable to create the zip. Since $zipfilename and $zipname is not defined, this won't work.

You should define $zipfilename with a ZIP filename and also use that same variable when creating the zip file.

Example:

    // a temp filename containing the current unix timestamp
    $zipfilename = 'temp_' . time() . '.zip';

    $zip->open($zipfilename, ZipArchive::CREATE);
    foreach ($files as $file) { 
       $zip->addFile($file); 
    } 
    $zip->close(); 

    header('Content-Type: application/zip'); 
    header('Content-disposition: attachment; filename=filename.zip'); 
    header('Content-Length: ' . filesize($zipfilename)); 
    readfile($zipfilename); 

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