In a Symfony2 project, you can configure the databases connections at the app/config/parameters.ini file. Documentation states that you can use, among others, sqlite3 PDO dr
According to Doctrine the elements used for sqlite DBAL configuration are:
This is also listed in the full reference for Doctrine configuration in Symfony2, although not elaborated on.
So you need to switch up your config params to match whats appropriate for sqlite.