NAME

Class::DBI::Loader::Relationship - Easier relationship specification in CDBI::Loader

SYNOPSIS

use Class::DBI::Loader::Relationship;

my $loader = Class::DBI::Loader->new( dsn => "mysql:beerdb",
                                      namespace => "BeerDB");

Now instead of saying

BeerDB::Brewery->has_many(beers => "BeerDB::Beer");
BeerDB::Beer->has_a(brewery => "BeerDB::Brewery");

BeerDB::Handpump->has_a(beer => "BeerDB::Beer"); 
BeerDB::Handpump->has_a(pub => "BeerDB::Pub");
BeerDB::Pub->has_many(beers => [ BeerDB::Handpump => 'beer' ]);
BeerDB::Beer->has_many(pubs => [ BeerDB::Handpump => 'pub' ]);

Just say

$loader->relationship( "a brewery produces beers" );
$loader->relationship( "a pub has beers on handpumps" );

And something like ( upgraded in v1.3 )

MyApp::Page->has_a( author => 'MyApp::User' );
MyApp::Page->has_many( revisions => 'MyApp::PageRevision' );

Just say

$loader->relationship( "a page has an user as author" );
$loader->relationship( "a page has many page_revisions as revisions" );

DESCRIPTION

This module acts as a mix-in, adding the relationship method to Class::DBI::Loader. Since Class::DBI::Loader knows how to map between table names and class names, there ought to be no need to replicate the names.

In addition, it is common (but not universal) to want reverse relationships defined for has-many relationships, and for has-a relationships to be defined for the linkages surrounding a many-to-many table.

The aim of CDBIL::Relationship is to simplify the declaration of common database relationships by providing both of these features.

The relationship takes a string. It recognises table names (singular or plural, for convenience) and extracts them from the "sentence".

AUTHOR

Simon Cozens, simon@cpan.org

Chunzi, chunzi@perlchina.org

SEE ALSO

Class::DBI::Loader.