How to Resolve Error Establishing Database in Wordpress (WP)

Error EStablihing a database connection

Maybe, i am amateur in Wordpress aka WP. In my case, my web client suddently erorr with message "ERROR ESTABLISHING A DATABASE CONNECTION". I am using IIS for Server and using Mysql Workbench to handle mysql. 

I am very confused about this case, because i am not build this web and i have to solved it. and i am noobs in WP. Which i know, if Error Establishing a database connection because my database not connect in my web? Why can occur, tomorrow my web work normally, and now suddenly error. I Dont know to explainded.

How to Solved this Problem ( I assumed your have database backup)

1. Check your database in your mysql server, phpmyadmin or mysql workbench, sql yog or another, why me suggested this. because "bim salabim" my database in mysql server lost like charm.
2. Create your new database with same name or different previous database ( in my case i am using same name, so as  not to change my file wp-config.php)
3. Import your database backup
4. Erorr When Export database,In my case this error message
5. ERROR 1813 (HY000) at line 52: Tablespace for table '`your_database`.`xxxx_commentmeta`' exists. Please DISCARD the tablespace before IMPORT.
6. Remove table xxx_commentmeta in .sql backup using notepad++ or another editor
7. and export again
8. Export finish
9. Refresh your site
10. and Done.. your site back again like charm.