How to change upload destination from public to private when there are uploaded files in database? [duplicate]

Question

There are a few fields that uses public upload destination. I changed it globally right now, as far as I know it uses private upload destination from now. But how can I change previously uploaded files' upload destination (programmatically)?

Answer 1

$dest = 'private://';
$file = file_move($file, $dest)

Change individual file from public to private and vice-versa