ruby-on-rails - 控制器上的 RoR 过滤器作为此 SQL

Question

如何在 Ruby on Rails 中的控制器上编写过滤器，相当于此 SQL 代码

select * from persons where persons.category = 'developers'

Answer 1

用这个：

before_filter :nerds_only

private

def nerds_only
  @people = Person.where(:category => 'developers')
end

Answer 2

您可能需要考虑创建一个命名范围来获取书呆子：

class Person < ActiveRecord::Base
  scope :developers, where(category: 'developers')
end

在您的控制器中：

before_filter :developers_only

private

def developers_only
  @people = Person.developers
end