ruby-on-rails - 如何搜索belongs_to关联属性

Question

我有两个实体Posts，Comments关联如下

class Post < ActiveRecord::Base
  attr_accessible :title, :msg
  has_many :comments
end

class Comment < ActiveRecord::Base
  attr_accessible :msg
  belongs_to :post
  scope :search, lambda { |msg| where(arel_table[:msg].matches('%#{msg}%'))}
end

现在scope :search只搜索，comments(msg)我想写另一个范围来搜索posts(msg)。comments

这个怎么写？

Answer 1

尝试以下方法（我更喜欢类方法而不是 lambda 作用域，因为它们看起来更干净且更易于阅读）

# comment.rb

def self.search(msg)
  where(arel_table[:msg].matches('%#{msg}%'))
end

def self.post_search(msg)
  joins(:post).where(Post.arel_table[:msg].matches("%#{msg}%"))
end