php - Laravel Time Difference Sum -

i have basic table captures sign in , out of member of staff.

i using laravel back-end , im struggling how total number of hours on site.

id | in_time   | out_time | in_date    | out_date 1  | 21:22:49  | 21:46:05 | 2016-01-28 | 2016-01-28 2  | 08:12:12  | 14:12:01 | 2016-01-28 | 2016-01-28 

see query far

$date1 = '2015-01-28'; $date2 = '2015-01-28';  $attendancehours = db::table('staff_attendances')->wherebetween('in_date', array($date1, $date2))->where('id', $sid)         ->get(); 

how output total hours on site daterange?

two ways go

1. use carbon see documentation on difference

   plenty of examples of on website

2. assuming using mysql use timestampdiff

   select timestampdiff(hour,'2003-02-01','2003-05-01 12:05:55');

   you can raw query in laravel like

   $attendancehours = db::select(     db::raw('timestampdiff(hour,concat(in_date," ",in_time),concat(out_date," ",out_time)'))->     table('staff_attendances')->     wherebetween('in_date', array($date1, $date2))->     where('id', $sid)     ->get(); 

warning: haven't tested above should work.