Database Error Occurred

I tried to migrate the database from one server to another.   

After set up the database and import mysql file.  I went to change information under 
application/config/database.php

'hostname' => 'localhost',
'username' => 'root',
'password' => '12345',
'database' => 'xxxxxx',
'dbdriver' => 'mysql',


However, I get the following error.

Unable to select the specified database: xxxxxxx
Filename: core/CodeIgniter.php
Line Number: 500


Please kindly advise where does it goes wrong.