has_many in Class:DBI

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

I am struggeling with Class::DBI. When the program runs I get this error:

Can't locate object method "kontakte" via package "Customercare::Kundenkontakte" at cc.pl line x.

What I really want is find a list of customer which had contact with my company. Like this:

01. Libary X
talk
postcard

02. Library Y
postcard

But I thought it's better to retrieve that list by asking for the contacts first. Can you help me?
Thanks,
Horshack

#!/usr/bin/perl
use strict;
# Buechereien -> german for Libraries
# Kundenkontakte -> german for customer-contacts
#
use Customercare::Buechereien;
use Customercare::Kundenkontakte;

my @kk = Customercare::Kundenkontakte->retrieve_all;

my $i = 0;
foreach (@kk) {
        last if $i++ > 10;
        printf "%02d. %s\n", $i, $_->customer->plzort;
        # This is where the problem occurs:
        foreach ( $_->kontakte ) {
                printf "  %s\n", $_->aktion_kurz;
        }
}

package Customercare::Buechereien;
use strict;
use base 'Customercare::DBI';

__PACKAGE__->set_up_table("buechereien");
__PACKAGE__->has_many(
        # This will create a new Method named "kontakte"
        "kontakte",
        'Customercare::Kundenkontakte' => "customer");

1;

package Customercare::Kundenkontakte;
use strict;
use base 'Customercare::DBI';

__PACKAGE__->set_up_table("kundenkontakte");
__PACKAGE__->has_a( customer => 'Customercare::Buechereien' );

1;


These are the tabledefinitions:

CREATE TABLE buechereien (
  customer varchar(50) NOT NULL default '',
  anschrift1 varchar(100) default NULL,
  plzort varchar(100) default NULL,
  tel varchar(50) default NULL,
  PRIMARY KEY  (customer)
) TYPE=MyISAM;

CREATE TABLE kundenkontakte (
  lfdnr int(11) NOT NULL auto_increment,
  customer varchar(50) NOT NULL default '',
  aktion_kurz varchar(50) NOT NULL default '',
  PRIMARY KEY  (lfdnr)
) TYPE=MyISAM;
[download]

Comment on has_many in Class:DBI Download Code

Replies are listed 'Best First'.
Re: has_many in Class:DBI by saintmike (Vicar) on Feb 16, 2004 at 00:18 UTC
Your `Customercare::Buechereien` package defines a has_many relationship to `Customercare::Kundenkontakte` -- but the application complains about Customercare::Kundenkontakte not having the desired relationship. Shouldn't it be the other way around, that the has_many relationship is defined in `Customercare::Kundenkontakte`?	[reply]
Re: has_many in Class:DBI by cees (Curate) on Feb 16, 2004 at 02:46 UTC
I don't think your problem is with Class::DBI, it is with perl. You have two nested foreach loops, and both use $_. Try the following and see what happens: `foreach my $buechereien (@kk) { last if $i++ > 10; printf "%02d. %s\n", $i, $buechereien->customer->plzort; # This is where the problem occurs: foreach my $kontakte ( $buechereien->kontakte ) { printf " %s\n", $kontakte->aktion_kurz; } }` [download] - Cees	[reply] [d/l]
Re: Re: has_many in Class:DBI by horshack (Acolyte) on Feb 16, 2004 at 07:28 UTC
You were both right. A nested double $_ and I tried to solve the problem down->up instead up->down. Thanks for your appreciated help! Horshack	[reply]