CODEWITHSUNDEEP
ruby-on-railsactiverecordeager-loading
Sean Magyar
Sean Magyar

Reputation: 2380

rails4 eager loading over 2 models

I'm not sure if I'm using properly the rails eager loading.

I'd like to call post.user.profile.first_name in the view which will be simply post.user.name thanks to delegation. I wanna do it with one query, so profile should be loaded along with user on the first query. I'm not sure if I'm doing it well.

Is this the way to go?

profile.rb

belongs_to :user

user.rb

has_one :profile
delegate :first_name, .... , to: :profile, allow_nil: true
has_many :posts

post.rb

belongs_to :user
has_one :user_profile, through: :user, source: :profile

posts_controller

Post.includes(:user, :user_profile).paginate.......

Upvotes: 0

Views: 27

Answers (1)

Peter P.
Peter P.

Reputation: 3517

Try: 

Post.joins(user: :profile).includes(user: :profile).paginate

The joins is to ensure an inner join for an efficient and accurate query. The includes is for the eager load, as you know.

Upvotes: 2

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