I could not find a clear explanation about what is a 'fid'. I got is an identifier for file in drupal, but no more than that. How it is generated? Is unique for any file? When it is used and why? Could someone give a clear explanation of this entity?
- You can find
fidunder the table name
- It is unique id for files. In files you can include images, .txt, .pdf etc extension files.
fidis unique for the site and
- By using
$fidis file id.
Fid is only valid for managed files. Files uploaded as unmanaged does not have records in database, so no fid.
Once file gets uploaded it stores the record to Database. The fid is file ID of the uploaded file.