Order by field in related model with ActiveRecord condition

Question

I am trying to order by a field in a related model in Rails. All of the solutions I have researched have not addressed if the related model is filtered by another parameter?

Item model

class Item < ActiveRecord::Base
  has_many :priorities

Related Model:

class Priority < ActiveRecord::Base
  belongs_to :item

  validates :item_id, presence: true
  validates :company_id, presence: true
  validates :position, presence: true
end

I am retrieving Items using a where clause:

@items = Item.where('company_id = ? and approved = ?', @company.id, true).all

I need to order by the 'Position' column in the related table. The trouble has been that in the Priority model, an item could be listed for multiple companies. So the positions are dependent on which company_id they have. When I display the items, it is for one company, ordered by position within the company. What is the proper way to accomplish this? Any help is appreciated.

PS - I am aware of acts_as_list however found it did not quite suit my setup here, so I am manually handling saving the sorting while still using jquery ui sortable.

Answer 1

You could use the includes method to include the build association then order by it. You just make sure you disambiguate the field you are ordering on and there are some things you should read up on here on eager loading. So it could be something like:

@items = Item.includes(:priorities).where('company_id = ? and approved = ?', @company.id, true).order("priorities.position ASC")