Rails scafolding associations has_many错误:1错误禁止保存此产品

class Product < ApplicationRecord
  has_many :comments
end

class CreateComments < ActiveRecord::Migration[6.0]
  def change
    create_table :comments do |t|
      t.text :content
      t.references :product, foreign_key: true

      t.timestamps
    end
  end
end

class CreateComments < ActiveRecord::Migration[6.0]
  def change
    create_table :comments do |t|
      t.text :content
      t.references :product, foreign_key: { to_table: :products, on_delete: :cascade }

      t.timestamps
    end
  end
end

rails destroy scaffold Product
rails destroy scaffold Comment
rails generate scaffold Product name:string
rails generate scaffold Comment content:text product:references