Rails Nested Joins

Question

Manufacturer

has_many :product

Product

has_many :part

PartsRequest

belongs_to :part
belongs_to :manufacturer 

I am trying to do something in PartsRequest e.g. Manufacturer A is trying to request for Parts from Manufacturer B

scope :incoming_requests, lambda { |manufacturer_id|
    joins(:part).joins(product).where("product.manufacturer_id = ?", manufacturer_id)
}

How do I join to parts, then from parts join with products?

Answer 1

scope :incoming_requests, lambda{|mid| joins(:part => :product).where(:product => {:manufacturer_id => mid}) }