Question

我正在构建一个类似reddit的应用程序，您可以在其中将提交内容添加到特定的用户页面。提交具有一些属性，包括名为 url 的属性。我想在添加新提交时检查该特定页面是否已经存在具有相同url的提交，如果存在，请对其投票，而不是将其创建为新提交。如果没有，只需将其添加为新提交。我在这里使用 act_as_votable 宝石。

这是创建方法：

def create
    @user = User.friendly.find(params[:user_id])
    @submission =  @user.submissions.new(submission_params)
    @submission.member_id = current_user.id
    @submission.creator_id = @user.id
    @submission.is_viewed = false
    @submission.get_thumb_and_title_by_url(@submission.url)
    respond_to do |format|
       if @submission.save

        format.html { redirect_to @user, notice: 'Submission was 
 successfully created.' }
        format.json { render :show, status: :created, location: @submission }
       else
           format.html { render :new }
           format.json { render json: @user.errors, status: :unprocessable_entity }
       end
     end
  end

Answer 1

您应该看看https://apidock.com/rails/v4.0.2/ActiveRecord/Relation/find_or_create_by和https://apidock.com/rails/v4.0.2/ActiveRecord/Relation/find_or_initialize_by

现在在您的代码上，我们可以进行

之类的更改

def create
    @user = User.friendly.find(params[:user_id]) 
    @submission =  @user.submissions.find_or_initialize_by(submission_params)
    if @submission.id.present? 
      # What to do if the record exists 
    else
      # if its a new record 
      @submission.member_id = current_user.id
      @submission.creator_id = @user.id
      @submission.is_viewed = false
      @submission.get_thumb_and_title_by_url(@submission.url)
    end


    respond_to do |format|
       if @submission.save

        format.html { redirect_to @user, notice: 'Submission was 
 successfully created.' }
        format.json { render :show, status: :created, location: @submission }
       else
           format.html { render :new }
           format.json { render json: @user.errors, status: :unprocessable_entity }
       end
     end
  end

我希望这可以使您走上正轨

快乐编码

如果具有相同属性的记录存在，则更改创建的行为

1 个答案: