ruby-on-rails – Rails 5活动记录记录无效错误

我有两个Rails模型,即Invoice和Invoice_details.
Invoice_details属于Invoice,Invoice有许多Invoice_details.
我无法使用Invoice中的accepts_nested_attributes_for通过Invoice模型保存Invoice_details.

我收到以下错误：

(0.2ms)  BEGIN
(0.2ms)  ROLLBACK
Completed 422 Unprocessable Entity in 25ms (ActiveRecord: 4.0ms)         
ActiveRecord::RecordInvalid (Validation failed: Invoice details invoice must exist):
app/controllers/api/v1/invoices_controller.rb:17:in `create'

以下是invoice.rb的代码段：

class Invoice < ApplicationRecord
  has_many :invoice_details
  accepts_nested_attributes_for :invoice_details
end

invoice_details.rb的代码段：

class InvoiceDetail < ApplicationRecord
  belongs_to :invoice
end

控制器代码：

class Api::V1::InvoicesController < ApplicationController
  respond_to :json

  def index
    comp_id = params[:comp_id]
    if comp_id
      invoices = Invoice.where(:company_id => comp_id)
      render json: invoices,status: 201
    else
      render json: { errors: "Company ID is NULL" },status: 422
    end
  end

  def create
    Rails.logger.debug invoice_params.inspect
    invoice = Invoice.new(invoice_params)
    if invoice.save!
      render json: invoice,status: 201
    else
      render json: { errors: invoice.errors },status: 422
    end
  end

  def invoice_params
    params.require(:invoice).permit(:total_amount,:balance_amount,:customer_id,invoice_details_attributes:[:product_id])
  end
end

传递给控制器??的原始JSON数据：

{
    "invoice":{
        "total_amount":"100","balance_amount":"0","customer_id":"1","invoice_details_attributes":[{
            "product_id":"4"
        }]
    }
}

invoice_details架构

|id | invoice_id | product_id | created_at | updated_at|

发票架构

|id| total_amount |balance_amount | generation_date | created_at | updated_at | customers_id|

def invoice_params
  params.require(:invoice).permit(:total_amount,invoice_details_attributes: [:product_id,:invoice_id])
end

class InvoiceDetail < ApplicationRecord
  belongs_to :invoice,optional :true
end