title: laravel excel - issue with creating export to xls
body: <p>I have problem with export data from database to xls file. My query return 6 columns but when I wan add next column it's not show up in xls file, it's shows only header. I checked the query and it's ok - returns what I want.</p>
  <p>my model class</p>
  <pre class="lang-php prettyprint-override"><code>class CarRaports implements FromCollection, WithHeadings
  {
      protected $date_from;
      protected $date_to;
      protected $user;
  
      function __construct($date_from, $date_to, $user)
      {
          $this-&gt;date_from = $date_from;
          $this-&gt;date_to = $date_to;
          $this-&gt;user = $user;       
      }
  
      public function collection()
      {
          return DB::table('cars')
                  -&gt;select([
                      'cars.id_number',
                      'users.nick',
                      'cars.date_from',
                      'cars.date_to',
                      'cars.price',
                      'cars.color',
                      DB::raw(&quot;CONCAT (client.name, ' ', client.prefix) AS client&quot;) // not shows up
                  ])
                  -&gt;join(&quot;users&quot;, &quot;users.id_user&quot;, &quot;=&quot;, &quot;cars.id_user&quot;)
                  -&gt;join(&quot;client&quot;, &quot;client.id_client&quot;, &quot;=&quot;, &quot;users.id_client&quot;)
                  -&gt;whereBetween('date', [$this-&gt;date_from, $this-&gt;date_to])
                  -&gt;where('users.id_user', '=', $user)
                  -&gt;orderBy('cars.id_number', 'asc')
                  -&gt;get();
  
      }
  
      public function headings(): array
      {
          return [&quot;Id_number&quot;, &quot;User&quot;, &quot;Date from&quot;, &quot;Date to&quot;, &quot;Price&quot;, &quot;Color&quot;, &quot;Client&quot;]; 
      }
  </code></pre>
  <p>and my controller function</p>
  <pre class="lang-php prettyprint-override"><code>...
       public function genRaport 
       {
          $date_from = $request-&gt;input(&quot;date_from&quot;);
          $date_to = $request-&gt;input(&quot;date_to&quot;);
          $user = $request-&gt;input(&quot;user&quot;);
  
          return \Excel::download(new UmowyRaport($date_from, $date_to, $user), 'raport_cars_'.date('d-m- 
          Y').'.xlsx');
       }
      
  </code></pre>