- 'table' => 'inventory_item',
- 'hashref' => { 'classnum' => $classnum,
- 'svcnum' => $old->svcnum,
- 'item' => $old->$field(),
- },
+ 'table' => 'inventory_item',
+ 'hashref' => { 'classnum' => $classnum,
+ 'svcnum' => $old->svcnum,
+ },
+ 'extra_sql' => ' AND '.
+ '( ( svc_field IS NOT NULL AND svc_field = '.$dbh->quote($field).' )'.
+ ' OR ( svc_field IS NULL AND item = '. dbh->quote($old->$field).' )'.
+ ')',