my $items = $self->db->resultset('Item')->search({},{
    '+select' => ...
    'join' => ...
    where => {
      -or => ...
      'start_datetime' => {'<=' => \'NOW()'},
      'end_datetime' => {'>=' => \'NOW()'},
    },
    group_by => ...
    order_by => ...
  });

##</code><code>##

foreach my $value(@values) {
  my $results = $items->search({ 'joined_table.column' => $value });

  # Process and output results of this search
  ...
}

##</code><code>##

my $results_query = $items->search({ 'joined_table.column' => '?' });

foreach my $value(@values) {
  my $results = $results_query->bind($value);

  # Process and output results of this search
  ...
}