Rails 5 ActiveRecord :: RecordInvalid（驗證失敗），但我沒有驗證

Question

我試圖實現一個has_many :through多對多的形式，但我有一個問題提交給數據庫。我沒有字段驗證，它告訴我它抱怨哈希參數的結構比什麼都重要。

的錯誤是：

的ActiveRecord :: RecordInvalid（驗證失敗：費用支出類別費用必須存在）：

參數哈希是這樣的：

參數：{「utf8」=>「✓」，「費用」=> {「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」=> 「創建費用」}

一件事我注意到它不會將:expense_id值添加到聯結表中。這應該通過accept_nested_attributes_for機制來完成，但事實並非如此。我開始認爲這是Rails 5的一個問題，因爲我有類似的關係和形式結構像這樣工作正常。你們看到我失蹤的東西嗎？

這裏是我的控制器：

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 

這裏是我的模型：

費用

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" %> 

這裏是從瀏覽器的形式的數據被提交：

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

這是因爲Rails在創建費用之前試圖創建ExpenseExpenseCategory。你必須定義;關於關聯的: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