title: Cakephp how to create virtual field based on another virtual field
body: <p>I have </p>
  
  <pre><code>Contact Table : id, first_name, last_name, company_id
  Company Table : id, name
  </code></pre>
  
  <p>I would like to create virtual field in Contact Table so it will appear "contactInCompany"</p>
  
  <pre><code>"first_name last_name - Company.name" e.g: Andre Robin - Google
  </code></pre>
  
  <p>How can I achieve this, I try this way but it does not work, it does not accept another virtual field as input</p>
  
  <pre><code>public $virtualFields = array(
      'companyName' =&gt; 'SELECT name FROM companies where id = Contact.company_id',
      'customerWithCompany' =&gt; "CONCAT(Contact.first_name, ' ', 
                                Contact.last_name, ' ', Contact.companyName, '')"     
      );
  </code></pre>
  
  <p>I also tried it this way and it does not work</p>
  
  <pre><code>'customerWithCompany' =&gt; "CONCAT(Contact.first_name, ' ', Contact.last_name, '-', 
                           SELECT name FROM companies where id = Contact.company_id)"
  </code></pre>
  
  <p>I need this quite often, I will use this to put in dropdown selectbox to select contact, so I would like to have the contact name shown together with the company</p>