Error establishing a database connection
After getting the Wordpress successfully setup, I have uploaded a theme to /tmp/wordpress/wp-content/themes. However, the uploaded theme does not show up in my Wordpress.
Desperately trying different methods, I accidentally entered sudo cp -a /tmp/wordpress/. /var/www/html again in the command list. Afterwards the website is down, and will show Error establishing a database connection & HTTP 500 Error. The condition remains the same after switching off and on the server again.
Is there anyway to solve the problem? I didn't backup and don't want to setup everything again...