I have upgraded database with automatic upgrade tool of wordpress. After that when I tried to login in wordpress admin area. I have received this error message:
Database Error: Can’t Select Database
– Verify the database name, username and password with database connection tool like PHPMyADmin or with any temporarily script.
– Check the database name, username and password are set correct in wp-config.php file.
– Check the prefix of the database in your hosting control panel [default wp_] and set it correct in the database.
If all these does not work then take a support from your hosting service provider.