Data Integrity

Be confident in your data. Less bugs. Moar happy.

Delivered at hsv.rb - http://www.meetup.com/hsv-rb/events/192571982/

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    EBUBT create_table :products do |t| t.string :description t.boolean :active t.decimal :price end
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    TUBUF product = Product.all.sample product.description => ?
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    TUBUF product = Product.all.sample product.description => “doge cannon”
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    TUBUF product = Product.all.sample product.description => ‘’
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    TUBUF product = Product.all.sample product.description => nil WOMP
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    TUBUF product = Product.all.sample product.active => ?
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    TUBUF product = Product.all.sample product.active => true
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    TUBUF product = Product.all.sample product.active => false
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    TUBUF product = Product.all.sample product.active => nil WAT
23. product = Product.new product.description.upcase NoMethodError: undefined method `upcase` for nil:NilClass
24. product = Product.new product.description.to_s.upcase
25. product.price * TAX_RATE NoMethodError: undefined method `*` for nil:NilClass
26. (product.price || 0) * TAX_RATE
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29. t.string :description, null: false t.boolean :active, null: false t.decimal :price, null: false
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31. product = Product.new product.description.upcase => “KITTEH GOOGLEH EYES” &WFSZ 4JOHMF 5JNF
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33. TUSJOHT t.string :description, null: false, default: ‘’
34. CPPMFBOT t.boolean :active, null: false, default: false
35. EFDJNBMT t.decimal :price, null: false
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37. TUSJOHT t.string :description, null: false, default: ‘’, limit: 100
38. EFDJNBMT t.boolean :active, null: false, scale: 2, precision: 5
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40. UIF
    EBUBT create_table :users do |t| t.string :email, null: false end
41. User.create(email: “jay@bignerdranch.com”) User.create(email: “jay@bignerdranch.com”) User.all => [#<User id: 1, email: “jay…”>, #<User id: 2, email: “jay…”>] who even are you???
42. validate :email, uniqueness: true
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44. robots.thoughtbot.com/the-perils-of-uniqueness-validations
45. JOEJDFT create_table :users do |t| t.string :email, null: false t.index :email, unique: true end
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47. UIF
    EBUBT create_table :purchases do |t| t.integer :product_id, null: false t.integer :user_id, null: false t.index %i(product_id, user_id), unique: true end
48. user = User.find(1) product = Product.find(1) Purchase.create(user: user, product: product) product.destroy Purchase.last => #<Purchase id: 1, product_id: 1, user_id: 1> _.product => nil but it dead???
49. dependent: :destroy dependent: :delete dependent: :delete_all
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51. user = User.find(1) product = Product.find(1) Purchase.create(user: user, product: product) product.delete Purchase.last => #<Purchase id: 1, product_id: 1, user_id: 1> WOMP
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    GPSFJHOFS create_table :purchases do |t| # … t.foreign_key :products, dependent: :delete t.foreign_key :users, dependent: :restrict end
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58. bignerdranch.com/blog/coding-rails-with-data-integrity ! bignerdranch.com/blog/coding-rails-with-data-integrity-part-2 ! bignerdranch.com/blog/coding-rails-with-data-integrity-part-3 CMPHT
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