如何将我的Rails应用程序从Sqlite3切换到postgresql ?

So I started working on a Rails app recently and we decided (well not me, the person working on it with me) that we should switch from Sqlite3 to Postgresql. I've installed Postgresql on our server properly, created the databases for dev, prod, and test, and updated my Gemfile and database.yml files with the code for Postgres. The thing I'm unsure of now, is how to switch out all the files in the db directory with the Postgres databases. Do I just delete the contents of the db directory in my app and run rake db:create? So I started working on a Rails app recently an