NAME
            Class::DBI - Simple Database Abstraction

SYNOPSIS
            package Music::DBI;
            use base 'Class::DBI';
            Music::DBI->set_db('Main', 'dbi:mysql', 'username', 'password');

            package Artist;
            use base 'Music::DBI';
            Artist->table('artist');
            Artist->columns(All => qw/artistid name/);
            Artist->has_many('cds', 'CD' => artist);

            package CD;
            use base 'Music::DBI';
            CD->table('cd');
            CD->columns(All => qw/cdid artist title year/);
            CD->has_many('tracks', 'Track' => 'cd', { sort => 'position' });
            CD->has_a(artist => 'CD::Artist');
            CD->has_a(reldate => 'Time::Piece',
                    inflate => sub { Time::Piece->strptime(shift => "%Y-%m-%d") },
                    deflate => 'ymd',
            }

            CD->might_have(liner_notes => LinerNotes => qw/notes/);

            package Track;
            use base 'Music::DBI';
            Track->table('track');
            Track->columns(All => qw/trackid cd position title/); 

            #-- Meanwhile, in a nearby piece of code! --#

            my $artist = Artist->create({ artistid => 1, name => 'U2' });

            my $cd = $artist->add_to_cds({ 
                    cdid   => 1,
                    title  => 'October',
                    year   => 1980,
            });

            # Oops, got it wrong.
            $cd->year(1981);
            $cd->commit;

            # etc.

            while (my $track = $cd->tracks) {
                    print $track->position, $track->title
            }

            $cd->delete; # also deletes the tracks

            my $cd  = CD->retrieve(1);
            my @cds = CD->retrieve_all;
            my @cds = CD->search(year => 1980);
            my @cds = CD->search_like(title => 'October%');

DESCRIPTION
    Class::DBI provides a convenient abstraction layer to a database.

    It not only provides a simple database to object mapping layer, but can
    be used to implement several higher order database functions (triggers,
    referential integrity, cascading delete etc.), at the application level,
    rather than at the database.

    This is particularly useful when using a database which doesn't support
    these (such as MySQL), or when you would like your code to be portable
    across multiple databases which might implement these things in
    different ways.

    In short, Class::DBI aims to make it simple to introduce 'best practice'
    when dealing with data stored in a relational database.

PRE-REQUISITES

	Class::DBI requires on several other modules. Installing via the
	CPAN shell should take care of all these for you. But if you need to
	install by hand you need to have the following:

	To run the module:

 		Class::Accessor          
		Class::Data::Inheritable
		Class::Trigger         
 		Ima::DBI
			(which in turn requires DBI itself, and Class::WhiteHole)

    To test the installation:
       Test::More
       DBD::SQLite
       DBD::mysql
       DBD::Pg
