So in Rails 4 the long desired feature to use not queries has been added.
not
Article.where.not(title: \'Rails 3\')
Has similar su
You can use Squeel for more complex queries:
Article.where{(title == 'Rails 3') | (title == 'Rails 4')}
This results in the following SQL query:
SELECT `articles`.* FROM `articles` WHERE ((`articles`.`title` = 'Rails 3' OR `articles`.`title` = 'Rails 4'))