Rails - Sort by join table data

Question

I\'ve got a RoR project in the works. Here are the applicable sections of my models.

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has_many :communities, :through => :ava         


        

Answer 1

You can also sort linked tables like this (e.g.):

class User
  has_many :posts
end

class Post
  belongs_to :user

  scope :sorted_by_user_and_title, -> { 
    joins(:user).merge(
     User.order(first_name: :asc, last_name: :asc)
    )
    .order(title: :desc)
    # SELECT * FROM `posts`
    # INNER JOIN `users` ON `posts`.`user_id` = `users`.`id`
    # ORDER BY
    # `users`.`first_name` ASC, `users`.`last_name` ASC, `posts`.`title` DESC;
  }
  scope :sorted_by_title_and_user, -> { 
    order(title: :desc)
    .joins(:user).merge(
     User.order(first_name: :asc, last_name: :asc)
    )
    # SELECT * FROM `posts`
    # INNER JOIN `users` ON `posts`.`user_id` = `users`.`id`
    # ORDER BY
    # `posts`.`title` DESC, `users`.`first_name` ASC, `users`.`last_name` ASC;
  }
end

Regards