Duplicate rows with Class::DBI

stonecolddevin has asked for the wisdom of the Perl Monks concerning the following question:

Hey all,
This is probably an ignorant question, but I'm having some trouble with Class::DBI retrieving all of the requested records from my database.

## index.cgi
#!perl -w

use strict;
use PL;

my $obj = PL->new;
my @info = $obj->DBI->Entries->retrieve_from_sql(qq{
        hidden = "n"
        ORDER BY date desc
        LIMIT 5
    });

my %data;
my @loop_data = ();


## NOT INCREMENTING PRIMARY KEY, THUS RETURNING THE FIRST ROW *TWICE*
for (@info) {
    $data{author}  = $_->author;
    $data{content} = $_->content;
    $data{title}   = $_->title;
    $data{id}      = $_->id;
    $data{date}    = $_->date;
    push @loop_data, \%data;
}


my %content = ( 
                title=>'Devin\'s Journal v.9', 
                body=>\@loop_data,                    # CRITICAL: must
+ be arrayref containing hashref, 
                                                    # DBI should be $s
+th->fetchrow_arrayref({});
                search=>'search?q=',                #to be defined in 
+Config.pm
                referer => $ENV{'REFERER'} ? $ENV{'REFERER'} : "none",
                IPAddy  => $ENV{'REMOTE_ADDR'}
        );

        
        
$obj->Template->file ("tmpl/main.tmpl");
print $obj->Template->format ( \%content );                

## PL::DBI::Entries.pm
package PL::DBI::Entries;
use strict;
use base 'PL::DBI';

sub new {
        my $class = shift;
        my $self  = {};
        bless $self, $class;
        return $self;
}

__PACKAGE__->columns( Primary => qw[id] );
__PACKAGE__->columns( All =>
            qw [ id       author 
                 title    date       
                 content  ip   ] );
                
__PACKAGE__->table('entries');


1;
[download]

It's retrieving two results, but it's the first record TWICE. What's going on here?

meh.

janitored by ybiC: Retitle from "Class::DBI" because one-word-node-titles hinder site search

Comment on Duplicate rows with Class::DBI Download Code

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Re: Duplicate rows with Class::DBI by friedo (Prior) on Apr 25, 2005 at 23:09 UTC
The problem lies here: `my %data; my @loop_data = (); ## NOT INCREMENTING PRIMARY KEY, THUS RETURNING THE FIRST ROW TWICE for (@info) { $data{author} = $_->author; $data{content} = $_->content; $data{title} = $_->title; $data{id} = $_->id; $data{date} = $_->date; push @loop_data, \%data; }` [download] Your hash, `%data`, is defined outside the lexical block of the for-loop. At the end of the for-loop, you push a reference to `%data` onto `@loop_data`. The problem is that the next time through the loop, you modify the same `%data`, which is already being referenced by `$loop_data[0]`, and push another reference to the same hash onto `$loop_data[1]`. Thus every element of `@loop_data` will be pointing to the same hash. You can fix this easily by declaring your `%data` hash inside the lexical block of your loop, so a new one gets created every time through the loop. `my @loop_data; for (@info) { my %data; $data{author} = $_->author; $data{content} = $_->content; $data{title} = $_->title; $data{id} = $_->id; $data{date} = $_->date; push @loop_data, \%data; }` [download] Update: Formatting errors.	[reply] [d/l] [select]
Re^2: Duplicate rows with Class::DBI by stonecolddevin (Parson) on Apr 25, 2005 at 23:13 UTC
Haha, friedo to the rescue yet again. I may have to write a perl meditation on that...;-) Worked like a charm, thanks very much :-) meh.	[reply]
Re^2: Duplicate rows with Class::DBI by eibwen (Friar) on Apr 26, 2005 at 00:37 UTC
Presuming that you want to push all the keys onto the array: `push @loop_data, \%$_ for (@info);`	[reply] [d/l]
Re^3: Duplicate rows with Class::DBI by friedo (Prior) on Apr 26, 2005 at 02:53 UTC
Why the `\%$_`? There's no need to copy `$_`'s referant, simply doing `push @loop_data, $_ for @info` would suffice. Of course, that's exactly the same as `@loop_data = @info`, so the whole thing is moot anyway. :)	[reply] [d/l] [select]