Yajra Datatable custom Model Attribute - laravel

Question

I'm using Yajra Datatables for Laravel and it won't show the custom attribute for my User model. This is my User model:
protected $appends = ['sum_work_hours'];
public function work_hours()
{
return $this->hasMany(WorkHour::class);
}
public function getSumWorkHoursAttribute()
{
return $this->work_hours->sum('hours_total');
}
And this is in Controller:
public function showHours()
{
return view('hour');
}
public function getHoursDatatable()
{
$users = User::select(['name', 'email', 'sum_work_hours']);
return Datatables::of($users)->make();
}
And in view:
<link rel="stylesheet" href="https://cdn.datatables.net/1.10.15/css/dataTables.bootstrap.min.css">
<div class="container">
<div class="row">
<div class="col-md-12">
<div class="panel panel-default">
<div class="panel-heading">All Working Hours</div>
<div class="panel-body">
<table id="users-table" class="table table-striped table-bordered">
<thead>
<tr>
<th>Name</th>
<th>Email</th>
<th>Sum Work Hours</th>
</tr>
</thead>
</table>
</div>
</div>
</div>
</div>
</div>
<script src="https://cdn.datatables.net/1.10.15/js/jquery.dataTables.min.js"></script>
<script src="https://cdn.datatables.net/1.10.15/js/dataTables.bootstrap.min.js"></script>
<script type="text/javascript">
$(function() {
$('#users-table').DataTable({
processing: true,
serverSide: true,
ajax: 'http://127.0.0.1:8000/datatables/get_hours_datatable',
columns: [
{ data: 'name' },
{ data: 'email' },
{ data: 'sum_work_hours' }
]
});
});
</script>
And this is what I get:
What could be wrong?

Answer 1

The problem was in my Controller
public function getHoursDatatable()
{
// this line was wrong
$users = User::select(['name', 'email', 'sum_work_hours']);
return Datatables::of($users)->make();
}
It should have been like this:
$users = User::with('work_hours')->get();
Now I get the results in my table.