作为此SQL的控制器上的RoR过滤器

Question

如何在Ruby on Rails中在控制器上编写过滤器，这相当于这个SQL代码

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

Answer 1

使用此：

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神经质：

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