CODEWITHSUNDEEP
ruby-on-railsrubyruby-on-rails-4activerecord
user3291025
user3291025

Reputation: 1117

Rails model method: which is preferable?

I am able to pass my model tests with two different approaches. Which is preferable? What approaches can I take to determine which is preferable, or if one is preferable? 

def queued_video?(video)
  queue_items.where(video: video.id).present?
end

vs

def queued_video?(video)
  queue_items.map(&:video).include?(video)
end

Upvotes: 1

Views: 85

Answers (1)

xlembouras
xlembouras

Reputation: 8295

I am assuming that queued_items is an ActivreRecord query.

I would not prefer the second because it evaluates all queue_items. The first is more efficient.

You can use any? instead of present? to make it feel more natural.

I think your best option is to use the exists? method of ActiveRecord

def queued_video(video)
  queue_items.exists?(video: video.id)
end

which results in a select 1 query

SELECT 1 AS one FROM `table_name` WHERE `table_name`.`video_id` = 123 LIMIT

and does exactly what you need in a more elegant way.

Upvotes: 3

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