Question

我有问题：我的表格就是那个

<%=form_for :abbonamentos, url: url_for( :controller => :abbonamentos, :action => :edit) do |f| %>

            <div class="field">
              <%= f.label :id%><br />
              <%= f.text_field :id%>
            </div> 
        <div class="actions">
            <%= f.submit %>
          </div> 
        <% end %>


        and my controller is that:


          def edit
                 id = params[:abbonamentos][:id]
                @b = Abbonamento.find_by_id(id)
                @user = current_user
                a=Abbonamento.find_by(user_id: @user.id)


            if a and @b
                a.update_column(:stato_ingresso, (a.stato_ingresso-1))
                @stato =  a.stato_ingresso
                flash[:success] = "Abbonamento used"
                redirect_to :scegli_posti
            else
                    flash.now[:error] = "Non ha abbonamento lo deve acquistare."
            end
          end

我想验证模型Abbonamento中是否存在params id ...当我尝试时我有这样的错误： AbbonamentosController＃edit中的NoMethodError 未定义的方法`[]'为nil：NilClass

谢谢

请可能是我无法解释自己。在我想做的研究中，我想用户已经在他的id（user_id）中注册了Abbonamento表。当用户在表abbonamento中注册时，将返回的注册是abbonamento_id，可以是1或2。当他想要使用订阅时，您必须在那里插入代码（abbonamento_id），以便应用程序可以在执行操作之前检查代码是对还是错。如果这是真的，应用程序将采取行动，否则它将成为另一个行动。实际上我会用rails来实现。谢谢

Started POST "/usa_abbonamento" for 127.0.0.1 at 2014-04-30 14:29:00 +0200
Processing by AbbonamentosController#edit as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"8Ydr6NPDkynPQd9zo42vgxNIsNSwz4SPkI0JNzfc4lQ=", "abbonamentos"=>{"id"=>"1"}, "commit"=>"Save Abbonamentos"}
  [1m[35mUser Load (0.4ms)[0m  SELECT "users".* FROM "users" WHERE "users"."remember_token" = 'c2bc8173fcb2c5cce4b2606962859049830be6aa' LIMIT 1
  [1m[36mAbbonamento Load (0.4ms)[0m  [1mSELECT "abbonamentos".* FROM "abbonamentos" WHERE "abbonamentos"."user_id" = 1[0m
  [1m[35mAbbonamento Load (0.3ms)[0m  SELECT "abbonamentos".* FROM "abbonamentos" WHERE "abbonamentos"."id" IS NULL
  Rendered abbonamentos/edit.html.erb within layouts/application (3.2ms)
  Rendered layouts/_header.html.erb (1.1ms)
  Rendered layouts/_footer.html.erb (0.1ms)
Completed 200 OK in 47ms (Views: 40.2ms | ActiveRecord: 1.2ms)

Answer 1

将您的控制器代码更改为

     def edit
             id = params[:abbonamentos][:id]
            @b = Abbonamento.where(:id => id)
            @user = current_user
            a=Abbonamento.where(:user_id => @user.id)


        if a.present? and @b.present?
            a.update_column(:stato_ingresso, (a.stato_ingresso-1))
            @stato =  a.stato_ingresso
            flash[:success] = "Abbonamento used"
            redirect_to :scegli_posti
        else
                flash.now[:error] = "Non ha abbonamento lo deve acquistare."
        end
      end

您可以使用present?或blank?方法检查行是否存在。

RAILS：在模型中搜索和修改列，其中包含从表格中传递的参数

1 个答案: