Tenants

tenants.rb

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'activerecord'
  gem 'mysql2'
end

require 'active_record'

ActiveRecord::Base.establish_connection(
  adapter:  'mysql',
  host:     'localhost',
  username: 'root',
  database: 'tenants'
)

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true
end

class Apartment < ApplicationRecord
  has_many :properties
  has_many :tenants, through: :properties
end

class Tenant < ApplicationRecord
  has_many :properties
  has_many :apartments, through: :properties
end

class Property < ApplicationRecord
  belongs_to :apartment
  belongs_to :tenant
end

def migrate
  ActiveRecord::Schema.define do
    create_table(:apartments) do |t|
      t.string :unit_number, null: false
    end

    create_table(:tenants) do |t|
      t.string :name, null: false
    end

    create_table(:properties) do |t|
      t.references :apartment, null: false, foreign_key: true
      t.references :tenant, null: false, foreign_key: true
    end
  end
end

migrate

puts 'Create Apartments'
apartment_records = 1_000_000.times.map do |i|
  { unit_number: "apartment_#{i}" }
end
Apartment.insert_all(apartment_records)

puts 'Create Tenants'
tenant_records = 1_000_000.times.map do |i|
  { name: "tenant_#{i}" }
end
Tenant.insert_all(tenant_records)

puts 'Create Properties'
apartment_ids = Apartment.pluck(:id)
tenant_ids = Tenant.pluck(:id)
property_records = tenant_ids.flat_map do |tenant_id|
  rand(4).times.map do |i|
    { tenant_id: tenant_id, apartment_id: apartment_ids.sample }
  end
end
property_records.each_slice(1000) do |slice|
  Property.insert_all(slice)
end