Rails 5 ActiveRecord :: RecordInvalid（验证失败），但我没有验证

Question

我试图实现一个has_many :through多对多的形式，但我有一个问题提交给数据库。我没有字段验证，它告诉我它抱怨哈希参数的结构比什么都重要。

的错误是：

的ActiveRecord :: RecordInvalid（验证失败：费用支出类别费用必须存在）：

参数哈希是这样的：

参数：{“utf8”=>“✓”，“费用”=> {“date”=>“2006/12/12”，“amount”=>“234”，“check_number”=>“234” “=>”0“，”notes“=>”234“，”expense_expense_categories_attributes“=> {”1464029611137“=> { “量”=> “234”， “expense_category_id”=> “1”， “_destroy”=> “假”}}}， “提交”=> “创建费用”}

一件事我注意到它不会将:expense_id值添加到联结表中。这应该通过accept_nested_attributes_for机制来完成，但事实并非如此。我开始认为这是Rails 5的一个问题，因为我有类似的关系和形式结构像这样工作正常。你们看到我失踪的东西吗？

这里是我的控制器：

def create 

    @expense = Expense.new(expense_params) 
    respond_to do |format| 
    if @expense.save! 
    @expenses = Expense.all.paginate(:page => params[:page], :per_page => 9).order("created_at DESC") 

     format.html { redirect_to @expense, notice: 'Expense was successfully created.' } 
     format.js {} 
     format.json { render json: @expense, status: :created, location: @expense } 
    else 
     @expenses = Expense.all.paginate(:page => params[:page], :per_page => 9).order("created_at DESC") 
     format.html { render action: "index" } 
     format.js {} 
     format.json { render json: @expense.errors, status: :unprocessable_entity } 
    end 
    end 
end 

def expense_params 
    params.require(:expense).permit(:id, :date, :amount, :check_number, :debit, :notes, :amount, :expense_expense_categories_attributes => [:id, :amount, :expense_id , :expense_category_id, :_destroy]) 
end 

这里是我的模型：

费用

class Expense < ApplicationRecord 
    has_one :payee 
    monetize :amount_cents 
    has_many :expense_expense_categories 
    has_many :expense_categories, through: :expense_expense_categories, :dependent => :destroy 
    accepts_nested_attributes_for :expense_expense_categories,:allow_destroy => true 

end 

ExpenseCategory：

class ExpenseCategory < ApplicationRecord 
    has_many :expense_expense_categories 
    has_many :expenses, through: :expense_expense_categories 

end 

ExpenseExpenseCategory

class ExpenseExpenseCategory < ApplicationRecord 
    monetize :amount_cents 
    belongs_to :expense 
    belongs_to :expense_category 

    accepts_nested_attributes_for :expense_category 
end 

_form.html.erb：

<%= form_for @expense, html: { :class => "ui form segment" }, :remote => true do |f|%> 

    <div class="field"> 

     <%= f.label :date%> 
     <div class="ui small input"> 
     <%= f.date_field :date %> 
    </div> 
    </div> 
    <div class="field"> 
    <%= f.label :amount %> 
    <div class="ui small input"> 

     <%= f.text_field :amount %> 
    </div> 

    </div> 

    <div class="field"> 
    <%= f.label :check_number %> 
    <div class="ui small input"> 

     <%= f.text_field :check_number %> 
    </div> 

    </div> 

    <div class="field"> 
    <%= f.label :debit %> 
    <div class="ui small input"> 
     <%= f.check_box :debit %> 
    </div> 

    </div> 

    <div class="field"> 
    <%= f.label :notes %> 
    <div class="ui small input"> 
     <%= f.text_area :notes %> 
    </div> 

    </div> 

    <%= f.fields_for :expense_expense_categories do |builders| %> 
     <%= render 'expense_expense_category_fields', :f => builders %> 
    <% end %> 
    <%= link_to_add_fields "Add Category", f, :expense_expense_categories %> 

    <%= f.submit class: "ui blue button" %> 

expense_expense_category_fields.htnl.erb

<div class="field"> 
    <%=f.label :amount%> 
    <%= f.text_field :amount %> 
</div> 
<div class="field"> 
    <%=f.label :category%> 
    <%= f.select :expense_category_id, ExpenseCategory.all.collect { |p| [p.category, p.id] } %> 
</div> 
<%= f.hidden_field :_destroy %> 

<%= link_to "Remove option", "#", :class => "remove_expense_expense_categories" %> 

这里是从浏览器的形式的数据被提交：

utf8:✓ 
expense[date]:2016-05-12 
expense[amount]:23 
expense[check_number]:23 
expense[debit]:0 
expense[notes]: 
expense[expense_expense_categories_attributes][1464030986149][amount]:23 
expense[expense_expense_categories_attributes][1464030986149][expense_category_id]:1 
expense[expense_expense_categories_attributes][1464030986149][_destroy]:false 
expense[expense_expense_categories_attributes][1464030991099][amount]:43 
expense[expense_expense_categories_attributes][1464030991099][expense_category_id]:10 
expense[expense_expense_categories_attributes][1464030991099][_destroy]:false 
commit:Create Expense 

Answer 1

这是因为Rails在创建费用之前试图创建ExpenseExpenseCategory。你必须定义;关于关联的:inverse_of。

class Expense < ApplicationRecord 
    has_one :payee 
    monetize :amount_cents 
    has_many :expense_expense_categories, inverse_of: :expense 
    has_many :expense_categories, through: :expense_expense_categories, :dependent => :destroy 
    accepts_nested_attributes_for :expense_expense_categories,:allow_destroy => true 

end 

class ExpenseCategory < ApplicationRecord 
    has_many :expense_expense_categories, inverse_of: :expense_category 
    has_many :expenses, through: :expense_expense_categories 

end 

class ExpenseExpenseCategory < ApplicationRecord 
    monetize :amount_cents 
    belongs_to :expense, inverse_of: :expense_expense_categories 
    belongs_to :expense_category, inverse_of: :expense_expense_categories 

    accepts_nested_attributes_for :expense_category 
end 

http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#module-ActiveRecord::Associations::ClassMethods-label-Setting+Inverses