WordPress cannot be installed

Prompt this error：
Error establishing a database connection
This either means that the username and password information in your wp-config.php file
is incorrect or we can’t contact the database server at localhost. This could mean your
host’s database server is down.

Are you sure you have the correct username and password?
Are you sure you have typed the correct hostname?
Are you sure the database server is running?
If you’re unsure what these terms mean you should probably contact your host. If you
till need help you can always visit the WordPress Support Forums.

The page I need help with: [log in to see the link]