NoMethodError in Maincat#get

Showing /var/www/root/apps/erolove/releases/20231230071111/app/views/maincat/get.html.haml where line #8 raised:

undefined method `parent_id' for #<ActiveRecord::Relation []>
Extracted source (around line #8):
6
7
8
9
10
11
              
%a{:href => "/"} Главная
= image_tag "bread.png"
- if !@cat.parent_id.blank?
- parent = Cat.where(id: @cat.parent_id)
- if !parent.blank?
- parent = Cat.where(id: parent.first.parent_id)

Rails.root: /var/www/root/apps/erolove/releases/20231230071111

Application Trace | Framework Trace | Full Trace

Request

Parameters:

{"url"=>"jeroticheskie-axessuary"}

Response

Headers:

None