# Terminal

bin/rails g model product name category sku in_stock:boolean

# db/migrate/20220501015917_create_products.rb
class CreateProducts < ActiveRecord::Migration[7.0]
  def change
    create_table :products do |t|
      t.string :name
      t.string :category
      t.string :sku, index: { unique: true }
      t.boolean :in_stock, default: true

      t.timestamps
    end
  end
end

Read Only Attributes

# models/product.rb
class Product < ApplicationRecord
  attr_readonly :sku
end

# Rails Console
product = Product.first
product.sku = "changedsku"
product.save # record updates, but sku attribute is ignored

Insert All

# Rails Console
products = [
  { name: 'Apple 14" Macbook Pro (2021)', category: "Laptop", sku: "MKGR3LL", in_stock: true },
  { name: 'Apple 16" Macbook Pro (2021)', category: "Laptop", sku: "MK1E3LL", in_stock: true },
  { name: 'Apple Mac Mini (2020)', category: "Desktop", sku: "MGNR3LL", in_stock: true },
  { name: 'Apple Mac Studio (2022)', category: "Desktop", sku: "MJMW3LL", in_stock: true }
]

Product.insert_all(products)

laptops = [
  { name: 'Apple 14" Macbook Pro (2021)', sku: "MKGR3LL", in_stock: true },
  { name: 'Apple 16" Macbook Pro (2021)', sku: "MK1E3LL", in_stock: true }
]

Product.create_with(category: "Laptop").insert_all(laptops)

Upsert

# Rails Console

desktops = [
  { name: 'Apple Mac Mini (2020)', category: "Desktop", sku: "MGNR3LL", in_stock: false },
  { name: 'Apple Mac Studio (2022)', category: "Desktop", sku: "MJMW3LL", in_stock: true }
]

Product.upsert_all(desktops, update_only: [:in_stock], unique_by: [:sku])

Toggle

# Rails Console
product = Product.first

product.toggle(:in_stock)
product.save

product.toggle!(:in_stock)

Single Table Inheritance

# Terminal
rails g model vehicle name type

# models/car.rb
class Car < Vehicle
  WHEELS = 4
end

# models/motorcycle.rb
class Motorcycle < Vehicle
  WHEELS = 2
end

# Rails Console
Car.create(name: "Civic")
Motorcycle.create(name: "Hayabusa")

vehicle = Motorcycle.first
vehicle.becomes(Car)

vehicle.becomes!(Car)
vehicle.save