how to change the sort order for the collection?

please help solve the problem.
tables:
users:
id: integer
name: varchar

posts:
id: integer
title: varchar
user_id: integer
views: integer

models:
User:
class User < ActiveRecord::Base
  has_many :posts, dependent: :destroy
end

Posts:
class Post < ActiveRecord::Base
  belongs_to :user
end

controller:
def popular_diary
  @diaries =
User.joins(:posts).group(:user_id).order('SUM(posts.views)')
end

the result @diaries contains a collection users, sorted by the number of
views. in ascending order (ASC). but I need to get a collection of
users, sorted in descending order (DESC).

I have tried to do so:
@diaries = User.joins(:posts).group(:user_id).order('SUM(posts.views)
:DESC')

but I got an error message:
SQLite3::SQLException: near ":DESC": syntax error: SELECT "users".* FROM
"users" INNER JOIN "posts" ON "posts"."user_id" = "users"."id" GROUP BY
user_id ORDER BY SUM(posts.views) :DESC

Remove semicolons.

DESC not :DESC. Remove semicolons.

thanks! thanks!