problem with rake and mysql

Hi, im a new with ruby
using ubuntu 10.04, when im create new project with sqlite3 adapter,
all works perfect
but when i create project with mysql db and type rails db:migrate
rakfile not found, and rakefile is absent in my app directory.
why it's not created with my app, as when im using sqlite3?
sry for my english

mysql (2.8.1)
mysql2 (0.2.4)
rails (3.0.1, 2.3.10)
railties (3.0.1)
rake (0.8.7)
sqlite3-ruby (1.3.1)