|-------------------|       |-------------------|
|  TBL NAME = Article   |       |  TBL NAME = Author  |     
|-------------------|       |-------------------|
| articleId  INT PrimKey |       | authorId  INT PrimKey|
| authorId  INT              |       |  articleId INT              |
| title varchar(255)        |       | author  varchar(32)    |
|other fields                  |       | other fields                |
---------------------      ---------------------

##</code><code>##

$article->author

##</code><code>##

package MPDatabase::Article;

use strict;
use base 'MPDatabase::DBI';

__PACKAGE__->table('article');
__PACKAGE__->columns(Primary => qw/articleId/);
__PACKAGE__->columns(All => qw/articleId topicId authorId title intro body postDateTime/);
__PACKAGE__->has_a(topicId  => 'MPDatabase::Topic');
__PACKAGE__->has_a(authorId => 'MPDatabase::Author');

__PACKAGE__->might_have( topic_class  => 'MPDatabase::Topic' => qw/topic relativeImagePath imagePath alt/);
__PACKAGE__->might_have( author_class => 'MPDatabase::Author' => qw/author email/);

1;

##</code><code>##

package MPDatabase::Author;

use strict;
use base 'MPDatabase::DBI';

__PACKAGE__->table('author');
__PACKAGE__->columns(Primary => qw/authorId/);
__PACKAGE__->columns(All => qw/authorId author email/);
__PACKAGE__->has_many(articles => 'MPDatabase::Article');

1;

##</code><code>##

!/usr/bin/perl -w
#
use strict;

use MPDatabase::Article;
use MPDatabase::Author;

my $article = MPDatabase::Article->retrieve(articleId => 5);
print $article->author, "\n";

# This program does not produce any output

##</code><code>##

<--- parse_params
mysql_st_internal_execute
Binding parameters: SELECT authorid
FROM   author
WHERE  authorid = '5'

##</code><code>##

SELECT authorId
FROM author A, article B
WHERE A.authorID = B.authorId and B.articleId = 5