Lägg till detta i gemfile
gem install mysql2
Och detta till database.yml
default: &default
adapter: mysql2
encoding: utf8
host: 127.0.0.1
port: 3306
development:
<<: *default
database: development_db_name
username: YOUR_USER_NAME
password: YOUR_PASSWORD
test:
<<: *default
database: test_db_name
username: YOUR_USER_NAME
password: YOUR_PASSWORD
production:
<<: *default
database: production_db_name
username: YOUR_USER_NAME
password: YOUR_PASSWORD