CODEWITHSUNDEEP
ruby-on-railspostgresql
goddamnyouryan
goddamnyouryan

Reputation: 6906

Rails Scope where most recent association is older than 1 month

I have two models in my app, one called Feed and one called Post. A feed has many posts.

I am looking for a way to return the feeds where the most recent post is older than 1 month.

I've got something simple like:

class Feed < ActiveRecord::Base
  has_many :posts

  scope :no_recent_posts, -> { includes(:posts).where('posts.created_at > ?', 1.month.ago) }
end

but of course this also returns any feeds if they have old posts (even if they have more recent ones too.

Maybe something with a limit(1) and an order?

Upvotes: 0

Views: 330

Answers (1)

Sean Hill
Sean Hill

Reputation: 15056

You can achieve this with a GROUP BY...HAVING.

scope :no_recent_posts, { joins(:posts).group(:feed_id).having('max(posts.created_at) > ?', 1.month.ago)

Since you don't really need to eager load the posts (based on your requirements), I changed the includes to a joins.

Upvotes: 2

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