RailsEnum map integer trong DB thành tên có nghĩa trong Ruby — giúp code đọc rõ hơn và tiết kiệm storage.
ruby
# Migration
add_column :orders, :status, :integer, default: 0
# Model (Rails 7+ dùng hash syntax)
class Order < ApplicationRecord
enum :status, { pending: 0, processing: 1, shipped: 2, delivered: 3, cancelled: 4 }
end
# Generated methods:
order.pending? # => true/false
order.processing! # update status = 1 ngay lập tức
Order.shipped # scope: WHERE status = 2
order.status # => "pending" (string)Lưu ý: dùng _prefix: hoặc _suffix: khi có nhiều enum trên cùng model để tránh conflict method name:
ruby
enum :status, { active: 0, archived: 1 }, _prefix: :status
enum :category, { active: 0, inactive: 1 }, _prefix: :category
# → status_active?, category_active?Enums map DB integers to meaningful names in Ruby — cleaner code and reduced storage.
ruby
# Migration
add_column :orders, :status, :integer, default: 0
# Model (Rails 7+ hash syntax)
class Order < ApplicationRecord
enum :status, { pending: 0, processing: 1, shipped: 2, delivered: 3, cancelled: 4 }
end
# Generated methods:
order.pending? # => true/false
order.processing! # updates status = 1 immediately
Order.shipped # scope: WHERE status = 2
order.status # => "pending" (string)Note: use _prefix: or _suffix: when a model has multiple enums to avoid method name collisions:
ruby
enum :status, { active: 0, archived: 1 }, _prefix: :status
enum :category, { active: 0, inactive: 1 }, _prefix: :category
# → status_active?, category_active?