if (!$form->{"delivery_order_items_id_$i"}) {
# there is no persistent id, therefore create one with all necessary constraints
my $q_item_id = qq|SELECT nextval('delivery_order_items_id')|;
my $h_item_id = prepare_query($form, $dbh, $q_item_id);
do_statement($form, $h_item_id, $q_item_id);
$form->{"delivery_order_items_id_$i"} = $h_item_id->fetchrow_array();
if (!$form->{"delivery_order_items_id_$i"}) {
# there is no persistent id, therefore create one with all necessary constraints
my $q_item_id = qq|SELECT nextval('delivery_order_items_id')|;
my $h_item_id = prepare_query($form, $dbh, $q_item_id);
do_statement($form, $h_item_id, $q_item_id);
$form->{"delivery_order_items_id_$i"} = $h_item_id->fetchrow_array();