Warning: file_get_contents(/data/phpspider/zhask/data//catemap/2/ruby-on-rails/59.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181
Ruby on rails 如何检查中是否存在父项具有多个关系_Ruby On Rails - Fatal编程技术网
Fatal编程技术网
  • ruby-on-rails/
  • Ruby on rails 如何检查中是否存在父项具有多个关系

Ruby on rails 如何检查中是否存在父项具有多个关系

ruby-on-rails

Ruby on rails 如何检查中是否存在父项具有多个关系,ruby-on-rails,Ruby On Rails,我有3种型号： User: has_many :comments Video: has_many :comments Comment: belongs_to :video, :user 视频/show.html.erb <%= form_for(@comment, :method => :post ) do |f| %> <%= f.text_area :body %> <%= f.hidden_field :video_id, :value =>"4

我有3种型号：

User: has_many :comments
Video: has_many :comments
Comment: belongs_to :video, :user
视频/show.html.erb

<%= form_for(@comment, :method => :post ) do |f| %>
<%= f.text_area :body %>
<%= f.hidden_field :video_id, :value =>"4" %>
<%= f.submit "submit" %>
<% end %>
在创建评论之前，如何检查视频的存在

这应该作为验证出现在您的评论模型中

class Comment < ActiveRecord::Base

  validates_presence_of :video

class注释
class Comment < ActiveRecord::Base

  validates_presence_of :video