title: How to add combined unique fields validator rule in Laravel 4
body: <p>I am using Laravel 4.2 and mysql db . <br> I have an exam table in which i am taking Exams entry and the fields are --> <br><code>id | examdate | batch | chapter | totalmarks</code> </p>
  
  <p>I have made a combined unique key using <br><code>$table-&gt;unique( array('examdate','batch','chapter') );</code> in schema builder.<br>Now I want to add a validation rule to it. I know i can add unique validation by <a href="http://laravel.com/docs/4.2/validation#rule-unique" rel="nofollow">laravel unique validator rule</a> but the problem is ,it checks only for one field .<br> I want it to add uniqueness to the 3 fields combined(user must not be able to add second row with same value combination of examdate,batch and chapter fields).</p>
  
  <p>Is it even possible to do it in laravel 4 .Is there any workaround if its not possible? </p>