ruby-on-rails - 更改连接表中的属性值时，Rails 5 正在插入而不是更新

Question

我有一个使用 has_many :through 关联的 HABTM 关系。我在更新连接表中的属性时遇到问题，因为它不是更新记录，而是在表中插入一条新记录，从而创建重复项。

我在创建索引和添加验证时尝试使用 UNIQUE 约束，但现在当我更新记录时出现验证错误或错误： ActiveRecord::RecordNotUnique in BatchesController#update Mysql2::Error: Duplicate entry

提供一些上下文：

• 我有 4 个表：manufacturing_orders、order_products、batches 和 batches_order_products（连接表）。
• 一个制造订单有许多订单产品。
• 此外，manufacturing_order 有很多批次。
• 批次有很多 order_products。
• 当我创建一个批次时，我复制了属于同一制造订单的所有订单产品，并以表格的形式为每个订单分配一个数量。

所以创建看起来工作正常，但是当我更新任何数量时，它只是再次插入整个关系而不是更新现有的。

模型制造订单.rb ：

class ManufacturingOrder < ApplicationRecord
  has_many :batches, inverse_of: :manufacturing_order, dependent: :destroy
  has_many :order_products, inverse_of: :manufacturing_order, dependent: :destroy

  accepts_nested_attributes_for :order_products
  accepts_nested_attributes_for :batches
end

模型order_product.rb：

class OrderProduct < ApplicationRecord

  belongs_to :manufacturing_order

  has_many :batches_order_products
  has_many :batches, :through => :batches_order_products
end

模型batch.rb：

class Batch < ApplicationRecord
  belongs_to :manufacturing_order

  has_many :batches_order_products
  has_many :order_products, :through => :batches_order_products

  accepts_nested_attributes_for :batches_order_products
end

模型batches_order_product.rb：

class BatchesOrderProduct < ApplicationRecord
  belongs_to :batch
  belongs_to :order_product

  validates :batch_id, uniqueness: { scope: :order_product_id }
end

控制器batches_controller.rb：

class BatchesController < ApplicationController
  def new
    manufacturing_order = ManufacturingOrder.find(params[:manufacturing_order_id])
    order_products = manufacturing_order.order_products
    @batch = Batch.new({
      manufacturing_order: manufacturing_order,
      order_products: order_products
    })
  end

  def create
    @batch = Batch.new(load_params)
    if @batch.save
      flash[:notice] = crud_success
      redirect_to action: :index
    else
      flash[:error] = @batch.errors.full_messages.to_sentence
      render action: :new
    end
  end

  def edit
    @batch = Batch.find(params[:id])
  end

  def update
    @batch = Batch.find(params[:id])
    if @batch.update_attributes(load_params)
      flash[:notice] = crud_success
      redirect_to action: :index
    else
      flash[:error] = @batch.errors.full_messages.to_sentence
      render action: :edit
    end
  end

  private
  def load_params
    params.require(:batch)
    .permit(:name,
      :date,
      :manufacturing_order_id,
      :status,
      order_products: [],
      order_products_ids: [],
      batches_order_products_attributes: [:id, :quantity, :order_product_id]
      )
  end
end

这是分批的形式：

  = bootstrap_form_for([@batch.manufacturing_order, @batch]) do |f|
    = f.hidden_field :manufacturing_order_id
       = f.text_field :name, label: 'Name'
        = f.text_field :date
    table
      thead
        tr
          th= "Product"
          th= "Quantity"
    tbody
      = f.fields_for :batches_order_products do |bop|
        = bop.hidden_field :order_product_id
      tr
        td
          = bop.object.order_product.name
        td
          = bop.text_field :quantity

  = f.submit 'Save'

任何帮助将不胜感激。谢谢！

更新：这些是提交编辑表单时传递的参数。有什么线索吗？

{"utf8"=>"✓",
 "_method"=>"patch",
 "batch"=>
  {"manufacturing_order_id"=>"8",
   "name"=>"MAS",
   "date"=>"07/05/2020",
   "batches_order_products_attributes"=>
    {"0"=>{"order_product_id"=>"12", "quantity"=>"77777777", "id"=>""},
     "1"=>{"order_product_id"=>"13", "quantity"=>"9.0", "id"=>""},
     "2"=>{"order_product_id"=>"14", "quantity"=>"7.0", "id"=>""}}},
 "commit"=>"Guardar",
 "manufacturing_order_id"=>"8",
 "id"=>"7"}

编辑 2：我更新了嵌套表单以将 id 包含在隐藏字段中，如下所示：

= f.fields_for :batches_order_products do |bop|
  = bop.hidden_field :order_product_id
  = bop.hidden_field :id, value: @batch.id

  = bop.object.order_product.name
  = bop.text_field :quantity, label: ''

但是现在 Rails 在更新时抱怨这个：

ActiveRecord::StatementInvalid in BatchesController#update

Mysql2::Error: Unknown column 'batches_order_products.' in 'where clause': SELECT `batches_order_products`.* FROM `batches_order_products` WHERE `batches_order_products`.`batch_id` = 9 AND `batches_order_products`.`` IN ('9', '9', '9', '9', '9') 

我不知道为什么 Rails 在 SQL 查询中添加了最后一个奇怪的部分。

标签： ruby-on-railsjoinactiverecordnested-forms

Answer 1

所以我终于想通了。

问题是连接表需要一个 ID 列来引用。该表有一个 batch_id 和 order_product_id 的索引，但由于某种原因它不起作用，ActiveRecord 正在寻找一个 ID。添加它解决了这个问题。

感谢@max 给出了一些值得关注的点。

class AddIndexToBatchesOrderProductsJoinTable < ActiveRecord::Migration[5.2]
  def change
    # add_index :batches_order_products, [:batch_id, :order_product_id], unique: true
    add_column :batches_order_products, :id, :primary_key
  end
end