Rails：查找has_one关系的记录

Question

我的用户模型有很多设计，而且还有很多design_request通过设计

现在我的design_request模型has_one命令。如何通过订单状态==“付费”为用户获取所有设计请求

my user model is below 
  ##User Model
  has_many :designs
  has_many :design_requests, through: :designs

  ##Design Model
  has_many :design_requests

 ##Design Request Model
   belongs_to :design
  belongs_to :user
  validates :business_name, :design_id, presence: true
  delegate :name, to: :design
  has_one :order, as: :item

Answer 1

你尝试过类似的事情吗？

user.design_requests.includes(:order).where(orders: {state: "paid"})

Answer 2

这有用吗？ user.design_requests.select {| dr | dr.order.state ==“付费”}