- my $hashref = { 'billpkgnum' => $self->billpkgnum };
- $hashref->{ 'classnum' } = $classnum if defined($classnum);
- @values = map { $_->amount } qsearch('cust_bill_pkg_detail', $hashref);
+ my $sql = 'SELECT SUM(COALESCE(amount,0)) FROM cust_bill_pkg_detail '.
+ ' WHERE billpkgnum = '. $self->billpkgnum;
+ $sql .= " AND classnum = $classnum" if defined($classnum);