Conversation over Configration 設定より規約に従う。 ex) model name of users table is User.rb
Do't Repeat Yourself ex) 同じことを繰り返さない
Representational State Transfer ex) user's resorces of URI is /users
gem installで railsもgem
bundler controls dependent of gem
MVC architecture
Model connection to database, business logic
View reference of Model, rendering of HTML
Controller call model, select view, connect model to view
1章
３大原則
gem installで railsもgem bundler controls dependent of gem
MVC architecture Model connection to database, business logic View reference of Model, rendering of HTML Controller call model, select view, connect model to view
2章
１件だけ取得 複数件取得 ActiveRecord::Relation where句 bundle して Scopeにできる default_scopeは毎回callされるのでattention
saveやvalid?でerrorsに格納