I am experiencing the same issue. Till yesterday it was all working fine and today morning it is giving “Error Establishing database connection” , check wp-config.php , tried repairing the database using “define( ‘WP_ALLOW_REPAIR’, true )”, still no luck.
I am scratching my head since last 4-5 hours.
I am using Xampp and mysql server is working just fine, i am able to access myphpadmin as well. I do not have updraft plus backup though, but I can download my live site data again as the last option. But that will take a lot of work again, any easy solution for this?