Should I be able to run two different “close” code versions of wordpress with the same DB

There are usually minimal db changes from one version to the next, it should be safe to do the manual-reinstall procedure with 1 older version.

You can see the changes it does in wp-admin/includes/upgrade.php

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