title: Set Unique Validation based on Category 1
body: <p>So I have 2 plugins, say for example <code>Categories</code> and <code>Sub Categories</code>.</p>
  <p>In <code>Categories</code> plugin I have 2 records <code>Category 1</code> and <code>Category 2</code>.</p>
  <p>In sub categories I have 2 fields .. 'Select Parent category' which will have a dropdown of <code>Categories</code> plugin, having dropdown values as <code>Category 1</code> and <code>Category 2</code> and another field as <code>name</code> in which I can add name of my sub category.</p>
  <p>Now I have set a unique validation for my <code>name</code> field something like this</p>
  <pre><code>public $rules = [
          'name' =&gt; 'required|unique:technobrave_supportcategories_,name',
      ];
  </code></pre>
  <p>This is working fine for me, however, I want unique validation based on my category_id as well ..  IS this possible ?</p>
  <p>I am trying this <a href="https://stackoverflow.com/a/50350625/6829420">https://stackoverflow.com/a/50350625/6829420</a> but its not working for me.</p>
  <p>Is this possible in OctoberCMS while adding/updating ? Please suggest me</p>
  <p>Thanks</p>