Install mysql2 gem on Snow Leopard for Rails 3 with rvm

Question

I have recently upgraded to Rails 3 and created a new application with Rails 3.0.3, but I keep getting an error

Macintosh:$ rails server
=> Booting WEBrick
=> Rai         


        

Answer 1

I actually had the wrong adaptor set on my database.yml

So the fix is

development:
  adapter: mysql2
  database: development_database
  username: root
  password:

Instead of

adapter: mysql

Doh!

Answer 2

If you're seeing this recently, it's because mysql2 0.3 removed the ActiveRecord Adapter, which is now part of Rails 3.1

WARNING: This version of mysql2 (0.3.2) doesn't ship with the ActiveRecord adapter bundled anymore as it's now part of Rails 3.1
WARNING: Please use the 0.2.x releases if you plan on using it in Rails <= 3.0.x

Adjust your Gemfile accordingly if you're on Rails 3.0.x

gem 'mysql2', '~> 0.2.6'