Loading SalesEngine data into ActiveRecord

sales_engine_active_record.rb

# https://github.com/JoshCheek/playgrounds                 <-- lots of examples (params, routes, etc)
# https://gist.github.com/JoshCheek/985a70527fa11a0123c5   <-- we got mass insertion working!
# s_arb                                                    <-- set language to ruby, then type that and press tab!
require 'active_record'
ActiveRecord::Base.establish_connection adapter: 'sqlite3', database: ':memory:'

ActiveRecord::Schema.define do
  self.verbose = false
  
  create_table :customers do |t|
    t.string :first_name
    t.string :last_name
    t.timestamps
  end
  
  create_table :invoices do |t|
    t.integer :customer_id
    t.integer :merchant_id
    t.string  :status
    t.timestamps
  end
end

class Customer < ActiveRecord::Base
  has_many :invoices
end

class Invoice < ActiveRecord::Base
  belongs_to :customer
end

require 'csv'
def load_csv(name, klass)
  filename = "/Users/josh/deleteme/sales_engines/sally-justin/data/#{name}.csv"
  CSV.foreach(filename, headers: true, header_converters: :symbol) { |row|
    klass.create! row.to_h
  }
end

load_csv 'customers', Customer
load_csv 'invoices',  Invoice

Customer.where(last_name: "Ullrich", first_name: 'Brice')
# => [#<Customer:0x007fd944da7ee0
#      id: 419,
#      first_name: "Brice",
#      last_name: "Ullrich",
#      created_at: 2012-03-27 14:55:51 UTC,
#      updated_at: 2012-03-27 14:55:51 UTC>]

Customer.find_by(id: 999)   # => #<Customer id: 999, first_name: "Clementina", last_name: "Hudson", created_at: "2012-03-27 14:58:15", updated_at: "2012-03-27 14:58:15">
        .invoices           # => #<ActiveRecord::Associations::CollectionProxy [#<Invoice id: 4833, customer_id: 999, merchant_id: 59, status: "shipped", created_at: "2012-03-17 19:58:15", updated_at: "2012-03-17 19:58:15">, #<Invoice id: 4834, customer_id: 999, merchant_id: 75, status: "shipped", created_at: "2012-03-19 10:58:15", updated_at: "2012-03-19 10:58:15">, #<Invoice id: 4835, customer_id: 999, merchant_id: 58, ...
        .pluck(:id)         # => [4833, 4834, 4835, 4836, 4837, 4838, 4839]