Error importing Database Back-up

Hi,
Before i upgrade to 7.19 (currently 7.18) I put my site in maintenance mode and backed up my database.
Thought id test to make sure it imports ok but keep getting this Error?

Any idea whats causing it please?

Error
SQL query:

--
-- Database: `mydatabase_`
--
CREATE DATABASE `mydatabase_` DEFAULT CHARACTER SET latin1 COLLATE latin1_swedish_ci;

MySQL said:

#1007 - Can't create database 'mydatabase_'; database exists