Friendly reminder that exists?, present? and any? behave differently than what you might expect.

rails.sh

irb(main):001:0> User.exists?
  users Columns (20.3ms)  SHOW FIELDS FROM `users`
  User Exists (0.3ms)  SELECT 1 AS one FROM `users` LIMIT 1
=> true
irb(main):002:0> User.where(:email => "foo").exists?
  User Exists (0.6ms)  SELECT 1 AS one FROM `users` WHERE `users`.`email` = 'foo' LIMIT 1
=> false
irb(main):003:0> User.where(:email => "foo").present?
   (0.7ms)  SELECT COUNT(*) FROM `users` WHERE `users`.`email` = 'foo'
=> false
irb(main):004:0> User.where(:email => "foo").any?
   (0.5ms)  SELECT COUNT(*) FROM `users` WHERE `users`.`email` = 'foo'
=> false