我有一个基于作用域的唯一性验证：validates :company_standard, uniqueness: { scope: :company_id } on a Rails Model X .
在所附的屏幕截图中，我试图通过表单（=标准流程）为该公司创建一个X类的新对象，没有激活company_standard字段或任何其他布尔字段。
但是，保存失败，在company_standard上出现uniqueness验证错误（参见屏幕截图）。
这个公司的类X的一个单独的对象存在于数据库中，其company_standard=true（我仔细检查了表单是否命名正确）。更新现有记录并将boolean字段设置为false似乎也会失败，并出现相同的验证错误。
不知道为什么会失败。在我看来是意料之外的行为。

@mechnicov评论后更新：型号

class MeanOfPayment < ApplicationRecord
      belongs_to :company
      has_many :in_payments
      has_many :out_payments
      has_many :bank_statements, dependent: :destroy
    
      validates :company_standard, uniqueness: { scope: :company_id }
    
      before_validation :remove_spaces
    
      def balance
        ...
      end
    
      def account_name
        ...
      end
    
      private
    
      def remove_spaces
        ...
      end
end

控制器

class Home::MeanOfPaymentsController < HomeController
  def index
    @title = t('titles.mean_of_payments.index')
    @mean_of_payments = current_company.mean_of_payments
  end

  def show
    @title = t('titles.mean_of_payments.show')
    @mean_of_payment = current_company.mean_of_payments.find(params[:id])
  end

  def new
    @title = t('titles.mean_of_payments.new')
    company_id = Company.find(params[:company_id]).id
    @mean_of_payment = MeanOfPayment.new(company_id: company_id)
  end

  def create
    fix_number(mean_of_payment_params[:balance_at_date])
    @mean_of_payment = (mean_of_payment_params[:type].constantize).new(mean_of_payment_params)
    if @mean_of_payment.save
      redirect_to home_company_mean_of_payments_path(Company.find(params[:company_id])), notice: t('mean_of_payment.notifications.create_successfully')
    else
      render :new
    end
  end

  def edit
    @title = t('titles.mean_of_payments.edit')
    @mean_of_payment = MeanOfPayment.find(params[:id])
  end

  def update
    fix_number(mean_of_payment_params[:balance_at_date])
    @mean_of_payment = MeanOfPayment.find(params[:id])
    if @mean_of_payment.update(mean_of_payment_params)
      redirect_to home_company_mean_of_payments_path(Company.find(params[:company_id])), notice: t('mean_of_payment.notifications.update_successfully')
    else
      render :edit
    end
  end

  def destroy
    mean_of_payment = MeanOfPayment.find(params[:id])
    company_id = mean_of_payment.company.id
    mean_of_payment.update!(marked_deleted: true)
    redirect_to home_company_mean_of_payments_path(company_id: company_id), method: :destroy, notice: t('mean_of_payment.notifications.delete_successfully')
  end

  private

  def mean_of_payment_params
    validation =  if params[:bank_account].present?
                    params.require(:bank_account)
                  elsif params[:cash_counter].present?
                    params.require(:cash_counter)
                  elsif params[:mean_of_payment].present?
                    params.require(:mean_of_payment)
                  else
                    raise "Zahlungsmethode muss im Controller eingeführt werden!"
                  end

    validation.permit(
        :account_name,
        :account_number,
        :balance_at_date,
        :balance_date,
        :bank_name,
        :bank_number,
        :company_id,
        :company_standard,
        :for_out_invoice,
        :owner,
        :primary_debitable,
        :type,
    )

  end
end

查看1 -新增

<div class="row">
  <div class="col-8 offset-2">
    <%= link_to t('common.buttons.back'), home_company_mean_of_payments_path %>
    <h1>
      <%= t('mean_of_payment.new.title') %>
    </h1>
    <%= render 'form', path: home_company_mean_of_payments_path(id: current_company.id) %>
  </div>
</div>

查看2 -表单

<%= simple_form_for @mean_of_payment, url: path do |f| %>
  <%= f.hidden_field :company_id, value: current_user.accounting_company.id %>
  <div class="row">
    <div class="col-6">
      <div class="ibox float-e-margins">
        <div class="ibox-content">
          <% if @mean_of_payment.errors.any? %>
            <div id="error_explanation">
              <h4><%= t('activerecord.errors.models.mean_of_payment.prohibited_save', count: @mean_of_payment.errors.count) %></h4>
              <ul>
                <% @mean_of_payment.errors.full_messages.each do |message| %>
                  <li><%= message %></li>
                <% end %>
              </ul>
            </div>
          <% end %>
          <div class="form-group">
            <%= f.label :type %>
            <%= f.select :type, options_for_mean_of_payment_general, class: 'form-control' %>
          </div>
          <div class="form-group">
            <%= f.label :bank_name %>
            <%= f.text_field :bank_name, class: 'form-control w-50' %>
          </div>
          <div class="form-group">
            <%= f.label :bank_number %>
            <%= f.text_field :bank_number, class: 'form-control w-50' %>
          </div>
          <div class="form-group">
            <%= f.label :account_name %>
            <%= f.text_field :account_name, class: 'form-control w-50'%>
          </div>
          <div class="form-group">
            <%= f.label :account_number %>
            <%= f.text_field :account_number, class: 'form-control w-50' %>
          </div>
          <div class="form-group">
            <%= f.label :owner %>
            <%= f.text_field :owner, class: 'form-control w-50' %>
          </div>
          <div class="form-group">
            <%= f.label :balance_at_date %>
            <%= f.text_field :balance_at_date, class: 'form-control w-50' %>
          </div>
          <div class="form-group">
            <%= f.label :balance_date %>
            <%= f.input :balance_date, as: :date, html5: true, class: 'form-control w-50', label: false %>
          </div>
          <div class="form-group">
            <%= f.label :company_standard %>
            <%= f.check_box :company_standard, class: 'form-control w-50' %>
          </div>
          <div class="form-group">
            <%= f.label :for_out_invoice %>
            <%= f.check_box :for_out_invoice, class: 'form-control w-50' %>
          </div>
          <div class="form-group">
            <%= f.label :primary_debitable %>
            <%= f.check_box :primary_debitable, class: 'form-control w-50' %>
          </div>
          <div class="form-group">
            <%= f.submit t('common.buttons.create_or_modify'), class: 'btn btn-primary' %>
          </div>
        </div>
      </div>
    </div>
  </div>
<% end %>