How Fragile Is DB if I Upload Completely Updated Files

Plugins and themes are dependent on the database!
I suggest you to:

  1. Upload the complete website. At this stage wordpress will start the usual setup from scratch.
  2. Install and activate this plugin: https://github.com/wp-sync-db/wp-sync-db
  3. Sync local db to production

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)