mysql - Rails - 连接表不会自动填充

Question

我的连接表不会从其来源的两个表中自动填充。我花了大约 5 个小时尝试以各种方式连接它，但无济于事。对我的代码的任何指导将不胜感激。

这是我的代码。

第一项:

`class Order < ActiveRecord::Base

  belongs_to :orders_users
  has_many :users, :through => :orders_users

  validates :item, presence: true

end

def add_order(order)
end

def remove_order(order)
end

`

第二项:

class User < ActiveRecord::Base
  belongs_to :orders_users
  has_many :orders, :through => :orders_users

  validates :username, presence: true, uniqueness: true
  has_secure_password
end

迁移:

class CreateJoinTable < ActiveRecord::Migration
  def change
    create_join_table :users, :orders do |t|
      t.index [:user_id, :order_id]
      t.index [:order_id, :user_id]
    end
  end
end

订单 Controller :

class OrdersController < ApplicationController


  def new
    binding.pry
    @order = Order.new
  end

  def create
    @order = Order.new(order_params)
    if @order.save
      redirect_to request.referer
    else
      redirect_to root_path
    end
  end

  def show
    @order
  end

  private

  def order_params
    params.require(:order).permit(:item)
  end



end

用户 Controller :

class UsersController < ApplicationController
  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)

    if @user.save
      session[:current_user_id] = @user.id
      redirect_to user_path(@user)
    else
      redirect_to new_user_path(@user)
    end
  end

  def show
    @user = User.find(params[:id])
  end

  def destroy
    @user = User.find(params[:id])
    session[:current_user_id] = nil
    @user.destroy
    redirect_to root_path
  end


  def index
    @user
  end

  private

  def user_params
    params.require(:user).permit(:username, :password,:password_confirmation)
  end


end

Answer 1

您混合了 Order 和 User 模型的关联。

您有 2 个选择。

1. 去掉“has many through”，使用HABTM(has and belongs to many)
2. 删除您的可联合对象并创建一个新的“真实”OrderUser 模型

选项 1将您的 User 和 Order 模型更改为:

class Order < ActiveRecord::Base
  has_and_belongs_to_many :users

  validates :item, presence: true

  def add_order(order)
  end

  def remove_order(order)
  end

end

class User < ActiveRecord::Base
  has_and_belongs_to_many :orders

  validates :username, presence: true, uniqueness: true
  has_secure_password
end

选项 2 has_many through

应该是has_many而不是belongs_to。

class Order < ActiveRecord::Base
  has_many :order_users
  has_many :users, :through => :order_users

  validates :item, presence: true

  def add_order(order)
  end

  def remove_order(order)
  end

end

class User < ActiveRecord::Base
  has_many :order_users
  has_many :orders, :through => :order_users

  validates :username, presence: true, uniqueness: true
  has_secure_password
end

回滚你的数据库以删除可连接的

rake db:rollback

使用 JoinTable 迁移删除旧的迁移文件。

创建一个“真实”模型以用于“has_many through”

rails g model OrderUser order:references user:references
rake db:migrate

关于如何验证 ActiveRecord 关系的提示

使用 Rails 控制台，这样您就不必担心 Controller 是否正常工作。一个小例子:

rails c
> u = User.create username: "test"
> o = u.orders.new item: "test-item"
> o.save

编辑您的订单 Controller

创建订单时，您必须在订单对象上指定 current_user。在示例中，我使用 current_user 获取签名用户，根据您的应用，您可能需要更改此设置。

class OrdersController < ApplicationController


  def new
    @order = Order.new
  end

  def create
    @order = Order.new(order_params)
    @order.users.build(current_user) #current_user is a function returning the signed in user
    if @order.save
      redirect_to request.referer
    else
      redirect_to root_path
    end
  end

  def show
    @order
  end

  private

  def order_params
    params.require(:order).permit(:item)
  end



end

Rails 指南中关于 has_many through 的一些信息