Question

在我的Rails应用程序中，我有people，可以有很多projects，反之亦然：

# app/models/person.rb
class Person < ActiveRecord::Base
  has_many :people_projects
  has_many :projects, :through => :people_projects
end

# app/models/people_project.rb
class PeopleProject < ActiveRecord::Base 
  belongs_to :person
  belongs_to :project 
end

# app/models/project.rb
class Project < ActiveRecord::Base
  has_many :people_projects
  has_many :people, :through => :people_projects

  def self.search(person_id)
    if person_id
      where("person_id = ?", person_id) # not working because no person_id column in projects table
    else
      scoped
    end
  end
end

如何在person_id的{{1}}视图中按index过滤项目，例如使用这样的网址：ProjectsController

我无法理解这一点。请帮忙！感谢...

Answer 1

您在项目表中不会有person_id，因为它具有has_many＆lt;＆gt; has_many关系。

简单@ person.projects将执行加入btw person_projects＆amp; project表并返回相应的项目。

*我假设，current_user返回一个Person对象。*

此外，完成您的模型定义。他们每个人都应该列出他们与PeopleProjects的关系

class Person < ActiveRecord::Base
  has_many :people_projects
  has_many :projects, :through => :people_projects
end

class Project < ActiveRecord::Base
  has_many :people_projects
  has_many :people, :through => :people_projects
end

Answer 2

Person和Project模型的关联定义不完整。您还需要has_many :people_projects定义。

# app/models/person.rb
class Person < ActiveRecord::Base
  has_many :people_projects # <-- This line
  has_many :projects, :through => :people_projects
end

# app/models/project.rb
class Project < ActiveRecord::Base
  has_many :people_projects # <-- This line
  has_many :people, :through => :people_projects
end

# app/models/people_project.rb
# This is defined correctly
class PeopleProject < ActiveRecord::Base
  belongs_to :person
  belongs_to :project
end

请参阅The has_many :through Association了解更多详情。

通过此定义，您将能够使用current_user.projects获取当前用户的所有项目，就像您在ProjectsController#index中已经完成的那样。

更新：

您可以在joins方法中使用includes或search并应用where条件。如下所示：

# app/models/project.rb
class Project < ActiveRecord::Base
  has_many :people_projects
  has_many :people, :through => :people_projects

  def self.search(person_id)
    if person_id
      includes([:people_projects, :people]).where("people.id = ?", person_id) 
    else
      scoped
    end
  end
end

如何在Rails中的连接表中获取相关记录？

2 个答案: