Database creation must be execute before the site generation

When the site is generated the follow message is displayed:

Make sure you update your database first before using the created entities:
    Directly update your database:          app/console doctrine:schema:update --force
    Create a Doctrine migration and run it: app/console doctrine:migrations:diff && app/console doctrine:migrations:migrate
    New DataFixtures were created. You can load them via: app/console doctrine:fixtures:load --append

So it assume that the database is already been created.