Laravel if conditon query

I have four input fields : Like this $cou = Input::get('activitycou'); $type = Input::get('activitytype'); $Des = Input::get('activityDes'); I do the following : If ($type!=null){ $query=Activity::where('id', $type)->get();
} If ($Des!=null){ $query=Activity::where('des_id', $Des)->get();
} etc However the problem is that $query is not displayed correctly can someone suggest a solution.