download blob image (stored in the database) to my computer

问题

i have blob images that are stored in the database I want to download it to my device.

• the image will be download (as ***.jpg) but it is corrupted . this is my download.php code

  <?php
  $servername = "localhost";
  $dbusername = "root";
  $dbpassword = "";
  $dbname = "text_blob1";
  $con= new mysqli($servername, $dbusername, $dbpassword, $dbname); 
  
  $id=$_GET["id"];
  $sql = "select * from table1 where id=$id "; // 1
  $res = $con->query($sql);
  while($row = $res->fetch_assoc())
   { 
   $name = $row['name'];
    echo "<br>";
   $size =  $row['size'];
    echo "<br>";
   $type = $row['extension'];
    echo "<br>";
   $image = $row['image'];
   }
  
    header("Content-type: ".$type);
    header('Content-Disposition: attachment; filename="'.$name.'"');
    header("Content-Transfer-Encoding: binary"); 
    header('Expires: 0');
    header('Pragma: no-cache');
    header("Content-Length: ".$size);
  
    echo $image;
    exit($image);   
     ?>
  

thanx <3

回答1:

Everything you output to the page is considered a file contents. I suppose you don't want "<br>" to be in the contents of your file.

Second point - do not do any output before setting headers.

Third point - exit('string') outputs 'string', so you output content of your file twice: with echo and with exit.

So, your code should look like:

$id=$_GET["id"];
$sql = "select * from table1 where id=$id "; // 1
$res = $con->query($sql);
while($row = $res->fetch_assoc())
{ 
    $name = $row['name'];
    $size =  $row['size'];
    $type = $row['extension'];
    $image = $row['image'];
}

header("Content-type: ".$type);
header('Content-Disposition: attachment; filename="'.$name.'"');
header("Content-Transfer-Encoding: binary"); 
header('Expires: 0');
header('Pragma: no-cache');
header("Content-Length: ".$size);

echo $image;
exit();

来源：https://stackoverflow.com/questions/43009763/download-blob-image-stored-in-the-database-to-my-computer