Partitional

gem 'partitional'

class ApplicationRecord
  include Partitional # Add this line to `app/models/application_record.rb`
end

# app/models/user.rb
class User < ApplicationRecord
  # `users` table has :email_local_part and :email_domain columns
  parition :email, prefix: :email # or mapping: { local_part: :email_local_part, domain: :email_domain }
end

# app/models/company.rb
class Company < ApplicationRecord
  # `companies` table has :contact_email_local_part, :contact_email_domain
  # :payment_email_local_part and :payment_email_domain columns

  partition :contact_email, class_name: 'Email', prefix: :contact_email
  partition :payment_email, class_name: 'Email', prefix: :payment_email
end

# app/models/email.rb
class Email < Partitional::Model
  attr_accessor :local_part, :domain

  validates :local_part, format: /\A[a-zA-Z0-9_-]{1,255}\z/
  validates :domain, format: /\A[a-zA-Z0-9]{2,}(?:\.[a-zA-Z0-9]{2,})+\z/

  def to_s
    "#{local_part}@#{domain}"
  end
end

# in some code
user = User.find(1)
user.email.local_part = "test"
user.email.domain = "example.com"
user.valid? # => true

user.email.domain = "!!!!"
user.valid? # => false