Question

We are in the midst of a data migration , and the project needs from one particular table BLOB data saved to files, and sent to the vendor, due to their structure

I am able to achieve this one at a time, but needed to create a batch process, as there are 50,000 rows/potential files.

my current code is

 $sql = "SELECT a.guid  AS file_name, a.attachment AS file_blob"
     ." FROM attachment a";


 $squery = oci_parse($link, $sql);
 oci_execute($squery);

 while ($row = oci_fetch_array($squery, OCI_ASSOC | OCI_RETURN_LOBS)) {
    header('Content-type: octet-stream;'); 
    header('Content-disposition: attachment;filename='.$row['FILE_NAME']);      
    print $row['FILE_BLOB']; 
    }

oci_free_statement($squery);

I do understand that I would rather be saving the data rather than streaming it to the browser, I just am not wrapping my head around how to achieve this, should i be looking at php file I/O fputs()?

End result is I would like the process to batch write binary files based on the query to a folder

EDIT

Thank you for your direction and help, based on that I ended up coming up with two separate ways to achieve this
first i did the following getcwd() to verify where the server was pointing to, and did an absolute path if needed

 $basedir = '/path/to/host/www/blobdoc/';

set permissions on the blobdoc folder then used either of the following scripts in the while loop

 $filename='';
 $filename=$basedir.$row['FILE_NAME'];
 file_put_contents( $filename, $row['FILE_BLOB']); 

 $filename='';
 $filename=$basedir.$row['FILE_NAME'];
 $File = @fopen( $filename, 'w' );      
 if( $File ) {
      if( FALSE === fwrite( $File, $row['FILE_BLOB'] ))
      return FALSE;
 fclose( $File );
 return TRUE;
 }

Answer 1

Instead of:

print $row['FILE_BLOB'];

Use something like:

file_put_contents( $filename, $row['FILE_BLOB']); //save locally

You need to write the blob to a file.

If you want to force a download of that file then you need to make use of the correct headers in combinarion with readfile, like so:

$file = '/var/www/html/file-to-download.zip'; 
header('Content-Description: File Transfer'); 
header('Content-Type: application/force-download'); 
header('Content-Length: ' . filesize($filename)); 
header('Content-Disposition: attachment; filename=' . basename($file)); 
readfile($file);