显示用户购买时出现错误，显示他购买的产品时出现产品图片和标题错误

Question

这是我在用户、Gig（产品）和记录购买的购买 table 之间的关系。

class User < ActiveRecord::Base
  has_many :gigs
  has_many :purchases, foreign_key: 'buyer_id'
  has_many :sales, foreign_key: 'seller_id', class_name: 'Purchase'
end

class Gig < ActiveRecord::Base
  has_many :purchases
  has_many :buyers, through: :purchases
  has_many :sellers, through: :purchases
end

class Purchase < ActiveRecord::Base
  belongs_to :gig
  belongs_to :buyer, class_name: 'User'
  belongs_to :seller, class_name: 'User'
end

记录我在我的控制器中使用的购买

 def downloadpage
    ActiveRecord::Base.transaction do
      if current_user.points >= @gig.pointsneeded 
        @purchase = current_user.purchases.create(gig: @gig, seller: @gig.user)
        if @purchase
          current_user.points -= @gig.pointsneeded
          @gig.user.points += @gig.pointsneeded
          current_user.save
          if @gig.user.save
            render 'successful_download', locals:{link:@gig.boxlink}
          end
        end
      else
        redirect_to :back, notice: "You don't have enough points"
      end
    end
  end

当买家从卖家那里购买东西时一切正常，积分在账户之间转移，买家被重定向到最终演出。

在我看来我可以做到

<h1>You downloaded <%= current_user.purchases.count %> boxes</h1>

它将显示 "gigs" 买家制作的数量。

现在我想显示的不仅仅是数字，还有产品的标题和图片他 bought.This 是我试过的

<div class="row experiment">
      <% current_user.purchases.each do |gig| %>
      <div class="well for-h1-gig-second col-xs-6 col-sm-4 col-lg-3 ">
        <%= link_to (image_tag gig.image.url(:medium), :class=>"img-responsive"), gig %>
        <h1><%= link_to gig.title, gig %></h1>
      </div>
      <% end %>
    </div>

但是它说找不到图片和标题。所以我尝试了 current_user.purchases.gig.each do |gig| 没有成功。

How do i fix it? P.S: Please feel free to edit my title,for future readers,i couldn't formulate it better,thank you.

Answer 1

尝试为用户添加关联：

class User < ActiveRecord::Base
  has_many :purchases, foreign_key: 'buyer_id'
  has_many :gigs, through: :purchases, source: :buyer
  has_many :sales, foreign_key: 'seller_id', class_name: 'Purchase'
end

那么你应该可以遍历 current_user.gigs

Answer 2

您的主要问题是 current_user.purchases.each 遍历购买 - 而不是演出。

<div class="row experiment">
    <% current_user.purchases.each do |purchase| %>
    <% gig = purchase.gig %>
    <div class="well for-h1-gig-second col-xs-6 col-sm-4 col-lg-3 ">
        <%= link_to(image_tag gig.image.url(:medium), :class=>"img-responsive"), gig %>
        <h1><%= link_to gig.title, gig %></h1>
    </div>
    <% end %>
</div>

还有其他一些问题：

class User < ActiveRecord::Base
  has_many :gigs # not going to work.
end

它不起作用的原因是 user 和 gig 之间的关系通过 purchases 以及 buyer_id 和 seller_id 外键. Rails 不支持依赖多个键的关系。

如果您想要 select 用户是卖家或买家的演出，您可以使用：

Gig.joins(:purchases).where('purchases.buyer_id=? OR purchases.seller_id=?', [current_user.id, current_user.id])

显示用户购买时出现错误，显示他购买的产品时出现产品图片和标题错误

Getting error when showing the purchases of the user,when showing the product he bought i get an error for product image and title

ruby

database

model-view-controller

model

ruby-on-rails-4