title: all queries are uppercase with oracle driver with laravel query builder
body: <p>I'm using <a href="https://github.com/yajra/laravel-oci8" rel="nofollow noreferrer">https://github.com/yajra/laravel-oci8</a> for connecting to oracle database in my project. 
  the problem is all of my queries turns to uppercase.</p>
  
  <pre><code>DB::table('users')-&gt;select('FirstName')-&gt;get();
  </code></pre>
  
  <p>this returns error saying invalid identifier "FIRSTNAME" </p>
  
  <pre><code>QueryException
  Error Code : 904
  Error Message : ORA-00904: "FIRSTNAME": invalid identifier
  Position : 69
  </code></pre>