Problem Migrating Rails 3.0.9 to Rails 3.1? ActiveRecord::ConnectionNotEstablished

I'm following chapter 2 of ruby.railstutorial.org and haven't able to connect to the DB on Rails 3.1.

My 开发者_运维问答guess is some gem in the Gemfile is missing.

I've tried using the provided Gemfile (to no avail, localhost doesn't even reach the server) and the default one. The default one gets me this:

How can I setup this Gemfile correctly for Rails 3.1?

It happened to me as well. Make sure you are running the latest sqlite3 gem.

In your Gemfile, relax the dependency to ~> 1.3.0, then update the Gemfile.lock by running

$ bundle update sqlite3