There are many reason’s why you might not know your MySQL username and password that is tied to your WordPress install.
Lately I’ve seen this a lot more because someone with enough know how click “Install WordPress” at their webhost provider and voila! They have WordPress installed.
When you want to move to a new domain or a different web host provider when you need to backup WordPress you might not be able to do so. One of the easiest ways of finding the MySQL Username and password is to FTP into your site and download the file called “wp-config.php”.
This file contains the information that you are so desperately looking for!
It will look like this:
Hope this helps you find out what your MySQL Username and password is for you WordPress install.