ActiveRecord::Associations [Rails]

ActiveRecord::Associations

• belongs_to
• has_one
• has_many
• has_and_belongs_to_many

参考：

ActiveRecord::Associations::ClassMethods | Ruby on Rails API [Official]

rails/associations.rb at v5.2.3 · rails/rails – GitHub

ActiveRecord::Associations::Association

参考：

rails/association.rb at v5.2.3 · rails/rails – GitHub

ActiveRecord::Associations::SingularAssociation

参考：

rails/singular_association.rb at v5.2.3 · rails/rails – GitHub

ActiveRecord::Associations::CollectionAssociation

参考：

rails/collection_association.rb at v5.2.3 · rails/rails – GitHub

ActiveRecord::Associations::Builder::HasOne

参考：

rails/has_one.rb at v5.2.3 · rails/rails – GitHub

ActiveRecord::Associations::Builder::HasMany

参考：

rails/has_many.rb at v5.2.3 · rails/rails – GitHub

ActiveRecord::Associations::Builder::Association

参考：

rails/association.rb at v5.2.3 · rails/rails – GitHub