Username has been exposed

Yes, the links will always be accessible unless you disable them on your htaccess or a PHP file. If you don’t have any author page, probably the users (or bots) that are reaching this page are seeing your index page.

I highly recommend you install Google Analytics code on your website to track what your users are seeing instead of a server log.

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