Unable to select the specified database: test

Dear All:
i am new in learning Codeigniter and i am in my second day in learning how to call database table contents to be displayed in a page, but for my sorry i always get this error, however; i give all privilleges to all users of local host, root, 127.0.0.1 
i tried many solutions as to change $db['default']['pconnect'] = TRUE; to false but it didn't work, so anyone can help?