my @items;
my $last_key;
while ($row = $sth->fetch_hashref()) {
   if (!@items || $last_key != $row->{item_key}) {
      push @items, {
         item_key         => $row->{item_key},
         item_description => $row->{item_description},
         item_summary     => $row->{item_summary},
         actions          => [],
      };

      $last_key = $row->{item_key};
   }

   push @{ $results[-1]{action} }, {
      key     => $row->{action_key},
      summary => $row->{action_summary},
   };
}