CODEWITHSUNDEEP
ruby-on-railsrubyactiverecordruby-on-rails-3.2
Mike R
Mike R

Reputation: 37

How do I optimize a select query in Activerecord?

I'm looking to see if there is a better way to write the following ActiveRecord query. 

@posts = Post.select {|x| x.section.nil?}

What I'm doing with this query is searching through posts and just selecting the posts that no longer have sections associated and are left orphaned.

Is there a better way to do this? I'm using rails 3.2.

Thanks so much.

Upvotes: 1

Views: 347

Answers (1)

Marek Lipka
Marek Lipka

Reputation: 51191

This should work:

Post.joins('left outer join sections on sections.id = posts.section_id').where('sections.id is null and posts.section_id is not null')

or in shorter way, using eager_load:

Post.eager_load(:section).where('sections.id is null and posts.section_id is not null')

Upvotes: 2

Related Questions