Question

我正在尝试创建一种关系，其中用户可以有很多订单和许多产品，一个订单可以有很多产品但属于一个用户，并且一个产品可以有很多用户和很多订单。

到目前为止，我有以下代码，以及上述三个模型以及一个联接表。我遇到的问题是，例如，每当尝试访问user.products时，都会出现uninitialized constant Order::ProductOrder错误，或者如果尝试product.orders时就会出现uninitialized constant Product::Orders。

有人会善待自己的经验来解决这个问题吗？

class Order < ApplicationRecord
  belongs_to :user
  has_many :product_orders
  has_many :products, through: :product_orders
end

class Product < ApplicationRecord
  has_many :product_orders, class_name: 'ProductOrders'
  has_many :orders, through: :product_orders
  has_many :users, through: :orders
end

class User < ApplicationRecord
  has_many :orders
  has_many :products, through: :orders
end

class ProductOrders < ApplicationRecord
  belongs_to :orders
  belongs_to :products
end

数据库架构：

  create_table "orders", force: :cascade do |t|
    t.datetime "fulfilled_date"
    t.integer "quantity"
    t.integer "total"
    t.bigint "user_id"
    t.index ["user_id"], name: "index_orders_on_user_id"
  end

  create_table "product_orders", force: :cascade do |t|
    t.bigint "product_id"
    t.bigint "order_id"
    t.index ["order_id"], name: "index_product_orders_on_order_id"
    t.index ["product_id"], name: "index_product_orders_on_product_id"
  end

  create_table "products", force: :cascade do |t|
    t.string "image_url"
    t.string "name"
    t.string "description"
    t.integer "inventory", default: 0
    t.integer "price"
    t.bigint "order_id"
    t.bigint "user_id"
    t.index ["order_id"], name: "index_products_on_order_id"
    t.index ["user_id"], name: "index_products_on_user_id"
  end

  create_table "users", force: :cascade do |t|
    t.string "name"
    t.string "email"
    t.string "address"
    t.string "state"
    t.string "zip"
    t.string "phone_number"
    t.string "country"
  end

Answer 1

需要更正的夫妇：

在class_name中为:product_orders添加Order；

class Order < ApplicationRecord
  belongs_to :user
  has_many :product_orders, class_name: 'ProductOrders'
  has_many :products, through: :product_orders
end

belongs_to应该具有单数order和product：

class ProductOrders < ApplicationRecord
  belongs_to :order
  belongs_to :product
end

Rails在多对多关系中统一误差

1 个答案: