I can not see the contents of the file after downloading?

I have a database that is storing all my pdf files for a website.

$params['name'] = $fields['title_name'];

$params['parent_id'] = $fields['uid'];

$params['name_file'] = strtolower($_FILES['fileToUpload']['name']);

$params['size_file'] = $_FILES['fileToUpload']['size'];

$params['type_file'] = $_FILES['fileToUpload']['type'];

!empty($_FILES) ? $params['data_file'] = base64_encode(file_get_contents($_FILES['fileToUpload']['tmp_name'])) : null;

Below you see the time of downloading the file, but when I open it I'm having an error that it is not content.

while($row = $this->db->getRow($result)) {

$type = $row['type_file'];

$size = $row['size_file'];

$filename = $row['name_file'];

$content = file_get_contents(''.$filename.'', base64_decode($row ['data_file']));

header("Content-length: $size");

header("Content-type: $type");

header("Content-Disposition: download; filename=$filename");

echo $content;

}

Is there a way we can do this?

The reason is that I do not want to use moveuploaded file into a folder.

Thank you.