On Feb 15, 2012, at 9:16 AM, tom wrote:
> I have a query as follows and it is giving an extra 'undef' result while
> fetching the results.
>
> my $item_cost_details_rs =
> $self->item_db()->resultset('ItemDetails');
> my @min_cost_items = $item_cost_details_rs->search(
> {},
> {
>
> join => 'item_mappings',
> select => [
> { min => 'item_mappings.item_mapping_cost' },
> 'item_mappings.item'
> ],
> as => [
> 'cost',
> 'item'
> ],
> group_by => [
> 'item_mappings.item'
> ]
> }
> );
> foreach my $row (@min_cost_items){
> my %details_item = $row->get_columns();
> use Data::Dumper::Simple;
> print STDERR Dumper(%details_item);
> }
>
>
> There are only 2 results to display. But in foreach loop it s getting an
> undef result in first looping. 2nd and 3rd looping give me the actual result.
>
> %details_item = (
> 'item' => undef,
> 'cost' => undef
> );
Offhand I don't know why you're seeing the problem you're seeing but I'd
suggest rewriting your loop using the next iterator rather than returning an
array of all results:
my $min_cost_items_rs = $item_cost_details_rs->search( ... );
while( my $row = $item_cost_items_rs->next ) {
...
}
In general this is a more efficient construct - the amount of memory it uses
should be independent of the size of the resultset. I suspect it will
coincidentally solve your problem.
- john romkey
http://romkey.com/
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