ruby-on-rails - 依次查找关联为nil的所有记录

Question

给定以下模型:

class Score < ApplicationRecord
  belongs_to :composition
end

class Composition < ApplicationRecord
  has_many :scores
  has_one :invoice, dependent: :destroy
end

class Invoice < ApplicationRecord
  belongs_to :composition
end

找到 分数 的最佳方法是什么，其组成有 nil invoice？

我试过:

Score.joins(:composition).where(composition: {invoice: nil})

csn = Composition.includes(:invoice).where(invoices:{id:nil})
Score.where(csn.include? composition)
Score.where(csn.map(&:id).include? composition_id)

Score.where(Composition.left_outer_joins(:invoice).where(invoices:{id:nil}).includes? composition)

全部有错误。有什么想法吗？

编辑:这里是根据schema.rb的相应表格:

  create_table "compositions", force: :cascade do |t|
    ...
  end

  create_table "invoices", force: :cascade do |t|
    t.integer  "composition_id"
    ...
    t.index ["composition_id"], name: "index_invoices_on_composition_id", using: :btree
  end

  create_table "scores", force: :cascade do |t|
    t.integer  "composition_id",                           null: false
    ...
  end

Answer 1

请尝试以下查询:

Score.joins(:composition).includes(composition: : invoice).where(invoices: { id: nil })