Alex Rivera | Logout

Rails: ActiveRecord Query for has_many :through model

Asked 2011-07-31T16:59:29.253
9

How to query for Companies with a certain Branch in a "has_many :through" relationship?

  #company.rb
  has_many :branch_choices
  has_many :branches, :through => :branch_choices

"Find all companies with Branch ID 3"

ruby-on-rails-3 activerecord has-many-through
Edit
Report

1 Answer

16
Company.includes(:branches).where(:branches => {:id => 3})

or

Branch.find(3).companies

UPDATE Actually, there's one downside to the first snippet: it eagerly loads branches along with the companies. To avoid this overhead you may consider using a left join:

Company.
  joins("LEFT JOIN `branch_choices` ON `branch_choices`.`company_id` = `companies`.`id`").
  where(:branch_choices => {:branch_id => 3})
answered 2011-07-31T17:01:17.517

Your Answer