03. Models - max-borisov/ihub-bookshelf GitHub Wiki

There will be 6 models:

  • user - manage user accounts
  • book - manage books
  • review - manage reviews
  • shopping_cart_item - manage user shopping cart
  • order - manage orders
  • order_item - manage order items

Lets generate models using rails generate command:

$ rails generate model book title:string author:string description:text price:'decimal{10,2}' pub_date:date amazon_id:string:uniq isbn:string:uniq

A new migration file file will be generated under db/migrate directory.

It will look like this:

class CreateBooks < ActiveRecord::Migration
  def change
    create_table :books do |t|
      t.string :title
      t.string :author
      t.text :description
      t.decimal :price, precision: 10, scale: 2
      t.date :pub_date
      t.string :amazon_id
      t.string :isbn

      t.timestamps null: false
    end
    add_index :books, :amazon_id, unique: true
    add_index :books, :isbn, unique: true
  end
end

$ rails generate model review text:text user:references book:references

$ rails generate model user name:string email:string:uniq admin:boolean

Open xxxxx_creare_users_.rb file under db/migrate folder and set default value for admin column:

class CreateUsers < ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.string :name
      t.string :email
      t.boolean :admin, default: false

      t.timestamps null: false
    end
    add_index :users, :email, unique: true
  end
end

$ rails generate model shopping_cart_item user:references book:references

$ rails generate model order user:references total_price:'decimal{10,2}'

$ rails generate model order_item order:references book:references

Example of migrations folder:

Migrations folder

It's time to apply migrations:

$ rake db:migrate

This command will create the database and models. Also db/schema.rb file is available now.

By the way, the following will return the list of all available rake commands:

$ rake -T

Helpful links