Yesterday I was able to log into the website no problem at all. Today if I try to view the website which is in a subdirectory http://www.solarbright.com.au/skylights I just get this error message "Error establishing a database connection". The site is set to automatically update and I suspect it may have something to do with an update done last night. I have viewed and worked my way through all the suggestions here https://codex.wordpress.org/Login_Trouble - but none of them have worked. I am still getting the same error. I have viewed the files on the server and everything is there. I have double checked everything suggested in the Login Trouble document.
Can anyone help, I have no idea what has happened as everything was working fine yesterday & if I have disabled both the theme & the plugins and it still doesn't work, I'm not sure what else could be causing the error.
Thank you in advance for your time.