[RESOLVED] Opened Mysql connections while files are uploading

2005

Hello,

I am going to change images upload script @ my website so that users can upload up to 10 images with one click. I allow 4 MB images and it may take a long time to upload 10X4MB=40 MB. I am getting confused about Mysql connection because all my php pages start with Mysql connection which is closed only when page is loaded. So, there will be a lot of opened connections while users upload files.

To avoid this I decided to change the script so that Mysql connection is opened and closed for each image when it's already uploaded. Is it OK to do so or it may cause some other problems?

Thanks.

if ( count($_FILES) > 0 )
{
...........................
	foreach($_FILES as $fileName=>$file)
	{
...........................

	if ( move_uploaded_file( $file['tmp_name'], $uploadfile ) )
	{


$link = mysql_connect(”localhost”, “mysql_username”, “mysql_password”);
mysql_select_db(”database”, $link);
mysql_query(”SELECT * FROM database”, $link);
mysql_close($link); 


}

}
}

ixalmida

I don't understand why you need to connect to mysql for every file. Are you trying to save the filename in the database? If so, the way you are doing it should be fine. If you are inserting files into your database as blobs, that is a different issue - and usually not recommended.

But if you just want to save the filenames (/locations) to your database, you could maybe optimize your code by creating a list of filenames and just running the query once:

$myfiles = array();

if ( count($_FILES) > 0 ) 
{ 
........................... 
    foreach($_FILES as $fileName=>$file) 
    { 
........................... 

    if ( move_uploaded_file( $file['tmp_name'], $uploadfile ) ) 
    { 
       array_push($myfiles, "(\'$fileName\')");
       ....................
    }
   }
}

$file_list = implode(", ", $myfiles);
// $file_list = "('file1'), ('file2'), ('file3')" ...etc
$query = "INSERT INTO files_table (filename) VALUES $file_list";

2005

Hello Ixalmida,

Thank you for your answer.
No, I am not saving files to the database. I am saving just file information - file name, description etc. Thank you for idea to create list of filenames.

NogDog

I'm not 100% sure about this, but I do not believe your PHP script actually gets called by the web server until all the post data is received. If this assumption is correct (can anyone here corroborate it?), then you should not need to worry about it.

Weedpacket

NogDog wrote:
If this assumption is correct

That's my assumption also; otherwise the $_FILES array would not be properly populated.

2005

Hello,
Probably I don't understand something, but there is a flash script in uploading process involved which calls php file. Files are being uploaded one by one. For example, if I am uploading 10 files, information about first file will be written to the DB as soon as it's uploaded ond only then starts uploading second file.

NogDog

2005;10920882 wrote:
Hello,
Probably I don't understand something, but there is a flash script in uploading process involved which calls php file. Files are being uploaded one by one. For example, if I am uploading 10 files, information about first file will be written to the DB as soon as it's uploaded ond only then starts uploading second file.

Still the same thing, it's just happening 10 times via 10 separate HTTP POST requests to the web server, which then fires off the target PHP script 10 separate times once each HTTP request (including the file upload) is completely received.

Weedpacket

Further, if the Flash app is making ten separate POSTs to the server to upload ten files, then the script that processes each POST will only have to deal with one uploaded file.