function getSum($periods, $glaccount_id = '', $glcentre_id = '')
{
$cc = new ConstraintChain();
// constrain glperiods_id by either a single, or an array of ids
if (is_array($periods)) {
$cc->add(new Constraint('glperiods_id', 'in', '(' . implode(',', $periods) . ')'));
} else {
$cc->add(new Constraint('glperiods_id', '=', $periods));
}
// constrain glaccount_id
if ($glaccount_id != '') {
$cc->add(new Constraint('glaccount_id', '=', $glaccount_id));
}
// constrain glcentre_id
if ($glcentre_id != '') {
$cc->add(new Constraint('glcentre_id', '=', $glcentre_id));
}
return parent::getSum('value', $cc, 'gl_balances');
}
