Rails order by association field

Question

I have the following models

class User   attr_accesible :first_name, :phone_number   has_one :user_extension end  class UserExtension   attr_accessible :company, :user_id   belongs_to :user end 

I have table which contains all users. And I need to sort this table by first_name, phone_number, company. With first_name, phone_number I don't have any problems, order works fine, in example

@users = User.order("first_name desc") 

, but I also need sort by company and don't know how to do it.

And I can get company name by this way

@user.user_extension.company 

So i have troubles with sql, which will gave me all users ordered by company. DB: PostgreSQL. Thanks.

Edit:

I should provide more information about this models.

create_table "user_extensions", :force => true do |t|   t.integer  "user_id"   t.string   "company" end  create_table "users", :force => true do |t|   t.string   "first_name"   t.string   "phone_number"  end 

Also, I tried use join

User.joins(:user_extension).order("user_extension.company desc") 

and what i get

 User Load (1.6ms)  SELECT "users".* FROM "users" INNER JOIN "user_extensions" ON "user_extensions"."user_id" = "users"."id" ORDER BY user_extension.company desc PG::Error: ERROR:  relation "user_extensions" does not exist 

on

User.includes(:user_extension).order("user_extension.company desc") 

i also get

PG::Error: ERROR:  relation "user_extensions" does not exist 

Resolved Have problems with my bd, all joins works fine.

Answer 1

Merge can make the query smaller/saner-looking, and it benchmarked faster for me in Rails 4.x:

@users = User.joins(:user_extension).merge(UserExtension.order(company: :desc)) 

Answer 2

Try this:

@users = User.includes(:user_extension).order("user_extensions.company desc") 

I think you need at order: user_extensions, not user_extension