title: Doctrine DQL - Select column alias added as new record
body: <p>I have a user entity linked to a user profile entity.</p>
  
  <p>I need to be able to concatenate a users first name and last name for filtering purposes.</p>
  
  <p>This is roughly how my query looks like :</p>
  
  <pre><code>$qb = $this-&gt;createQueryBuilder('users');
  $qb
      -&gt;addSelect('users')
      -&gt;innerJoin('users.profile', 'profile')
      -&gt;addSelect('profile')
      -&gt;addSelect('CONCAT(profile.firstName, \' \', profile.lastName) AS fullName')
  ;
  </code></pre>
  
  <p>I would expect the fullname to be treated as a user property, or profile, but instead i get the fullName as a whole new record in the results:</p>
  
  <pre><code>[0] =&gt; Array (
      [id] =&gt; 5
      [username] =&gt; admin
      [profile] =&gt; Array (
          [firstName] =&gt; John
          [lastName] =&gt; Doe
      )
  ), 
  [fullName] =&gt; John Doe
  </code></pre>
  
  <p>I tried aliasing the column as "users.fullName" but that gives me an error.</p>
  
  <p><strong>[Syntax Error] line 0, col 87: Error: Expected Doctrine\ORM\Query\Lexer::T_FROM, got '.'</strong></p>
  
  <p>What is the proper way to do this ?</p>
  
  <p>Thanks</p>