ruby-on-rails - 单表继承 Ruby on Rails 5.2

Question

I have three models User, Individual and Business. I also created three tables one for each. My individual and user table are identical so i inherited from user.rb My problem was when i came to the business.rb, i was able to access all of the parent attributes of User (example: first_name) but i could not access the model specific attributes (example: company_name) which are in the businesses table.

class User < ApplicationRecord
  # This is the user model
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable,
         :confirmable, :lockable, :timeoutable
  enum status: {unverified: 0, verified: 1}
end


# This is the business model
class Business < User
end
individual.rb
# # This is the individual model
class Individual < User
end
schema.rb
 # This is the schema for all the models
ActiveRecord::Schema.define(version: 2018_06_09_091056) do
  create_table "businesses", force: :cascade do |t|
    t.string "company_address"
    t.string "company_name"
    t.string "company_phone_number"
    t.text "documents"
  end
  create_table "individuals", force: :cascade do |t|
  end
  create_table "users", force: :cascade do |t|
    t.string "first_name"
    t.string "last_name"
    t.integer "status", default: 0
    t.string "date_of_birth"
    t.text "passport"
    t.string "country"
    t.string "personal_address"
    t.text "recovery_photo"
    t.string "type"
    t.string "email", default: "", null: false
    # etc..
  end
end

Answer 1

之所以称为单表继承是因为:所有数据都存储在单个表中。

写class Individual < User ，您正在将此模型的数据存储在 users 中表。

这些记录的唯一区别在于 individual.type == 'Individual' .

individuals和 businesses在您当前的设计中，表格从未使用过。

话虽如此，下面是我将如何更改它:

class User < ApplicationRecord
  # This is the user model
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable,
         :confirmable, :lockable, :timeoutable
  enum status: {unverified: 0, verified: 1}
end

# app/models/individual.rb
class Individual < User
end

# app/models/business.rb
class Business < User
  has_one :business_attributes
end

# app/models/business_attributes.rb
class BusinessAttributes < ApplicationRecord
  belongs_to :business
end

# db/schema.rb
ActiveRecord::Schema.define(version: 2018_06_09_091056) do
  create_table "business_attributes", force: :cascade do |t|
    t.string "company_address"
    t.string "company_name"
    t.string "company_phone_number"
    t.text "documents"
  end
  create_table "users", force: :cascade do |t|
    t.string "first_name"
    t.string "last_name"
    t.integer "status", default: 0
    t.string "date_of_birth"
    t.text "passport"
    t.string "country"
    t.string "personal_address"
    t.text "recovery_photo"
    t.string "type"
    t.string "email", default: "", null: false
    # etc..
  end
end