Eager loading nested, repeated models?

Question

Lets say I have a project model which has many members and many tasks.

class Project < ActiveRecord::Base
  has_many :memberships
  has_many :members, :through => :memberships, :class_name => 'User'
  has_many :tasks
end

When a task is created in the project, we keep a record of which user created it. Only users who are a member of the current project can

class Task < ActiveRecord::Base
  belongs_to :creator, :class_name => 'User'
  belongs_to :project
end

In my projects#show action, I want to find a project and display it along with it's members, tasks and their creators. I try to eager load these things in order to speed up the query.

Since I am eager loading the searches members, and tasks can only have a creator who is a member, am I right in thinking that I don't have to include the task's creator specifically?

In other words, can I do this:

Search.includes(:members, :tasks)

or should I do this:

Search.includes(:members, :tasks => :creator)

I think you will need to explicitly include :creator otherwise it will query for it when you access the creator, because there is no way rails can know that creator is one of the already queried members. — Abid, May 03 '12 at 22:28
@Abid It looks like you are correct. If you would like to move your comment into an answer I will accept it. — David Tuite, May 23 '12 at 14:06

score 1 · Accepted Answer · answered May 23 '12 at 17:37

1

I think you will need to explicitly include :creator otherwise it will query for it when you access the creator, because there is no way rails can know that creator is one of the already queried members

answered May 23 '12 at 17:37

Abid

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Eager loading nested, repeated models?

1 Answers1