NAME
DBIx::Class - Extensible and flexible object <-> relational mapper.
SYNOPSIS
Create a schema class called DB/Main.pm:
package DB::Main;
use base qw/DBIx::Class::Schema/;
__PACKAGE__->load_classes();
1;Create a table class to represent artists, who have many CDs, in DB/Main/Artist.pm:
package DB::Main::Artist;
use base qw/DBIx::Class/;
__PACKAGE__->load_components(qw/PK::Auto Core/);
__PACKAGE__->table('artist');
__PACKAGE__->add_columns(qw/ artistid name /);
__PACKAGE__->set_primary_key('artistid');
__PACKAGE__->has_many(cds => 'DB::Main::CD');
1;A table class to represent a CD, which belongs to an artist, in DB/Main/CD.pm:
package DB::Main::CD;
use base qw/DBIx::Class/;
__PACKAGE__->load_components(qw/PK::Auto Core/);
__PACKAGE__->table('cd');
__PACKAGE__->add_columns(qw/ cdid artist title year /);
__PACKAGE__->set_primary_key('cdid');
__PACKAGE__->belongs_to(artist => 'DB::Main::Artist');
1;Then you can use these classes in your application's code:
# Connect to your database.
use DB::Main;
my $schema = DB::Main->connect($dbi_dsn, $user, $pass, \%dbi_params);
# Query for all artists and put them in an array,
# or retrieve them as a result set object.
my @all_artists = $schema->resultset('Artist')->all;
my $all_artists_rs = $schema->resultset('Artist');
# Create a result set to search for artists.
# This does not query the DB.
my $johns_rs = $schema->resultset('Artist')->search(
# Build your WHERE using an SQL::Abstract structure:
{ name => { like => 'John%' } }
);
# Execute a joined query to get the cds.
my @all_john_cds = $johns_rs->search_related('cds')->all;
# Fetch only the next row.
my $first_john = $johns_rs->next;
# Specify ORDER BY on the query.
my $first_john_cds_by_title_rs = $first_john->cds(
undef,
{ order_by => 'title' }
);
# Create a result set that will fetch the artist relationship
# at the same time as it fetches CDs, using only one query.
my $millennium_cds_rs = $schema->resultset('CD')->search(
{ year => 2000 },
{ prefetch => 'artist' }
);
my $cd = $millennium_cds_rs->next; # SELECT ... FROM cds JOIN artists ...
my $cd_artist_name = $cd->artist->name; # Already has the data so no query
my $new_cd = $schema->resultset('CD')->new({ title => 'Spoon' });
$new_cd->artist($cd->artist);
$new_cd->insert; # Auto-increment primary key filled in after INSERT
$new_cd->title('Fork');
$schema->txn_do(sub { $new_cd->update }); # Runs the update in a transaction
$millennium_cds_rs->update({ year => 2002 }); # Single-query bulk updateDESCRIPTION
This is an SQL to OO mapper with an object API inspired by Class::DBI (and a compatibility layer as a springboard for porting) and a resultset API that allows abstract encapsulation of database operations. It aims to make representing queries in your code as perl-ish as possible while still providing access to as many of the capabilities of the database as possible, including retrieving related records from multiple tables in a single query, JOIN, LEFT JOIN, COUNT, DISTINCT, GROUP BY and HAVING support.
DBIx::Class can handle multi-column primary and foreign keys, complex queries and database-level paging, and does its best to only query the database in order to return something you've directly asked for. If a resultset is used as an iterator it only fetches rows off the statement handle as requested in order to minimise memory usage. It has auto-increment support for SQLite, MySQL, PostgreSQL, Oracle, SQL Server and DB2 and is known to be used in production on at least the first four, and is fork- and thread-safe out of the box (although your DBD may not be).
This project is still under rapid development, so features added in the latest major release may not work 100% yet -- check the Changes if you run into trouble, and beware of anything explicitly marked EXPERIMENTAL. Failing test cases are *always* welcome and point releases are put out rapidly as bugs are found and fixed.
Even so, we do our best to maintain full backwards compatibility for published APIs, since DBIx::Class is used in production in a number of organisations. The test suite is quite substantial, and several developer releases are generally made to CPAN before the -current branch is merged back to trunk for a major release.
The community can be found via:
Mailing list: http://lists.rawmode.org/mailman/listinfo/dbix-class/
SVN: http://dev.catalyst.perl.org/repos/bast/trunk/DBIx-Class/
Wiki: http://dbix-class.shadowcatsystems.co.uk/
IRC: irc.perl.org#dbix-classWHERE TO GO NEXT
DBIx::Class::Manual::DocMap lists each task you might want help on, and the modules where you will find documentation.
AUTHOR
mst: Matt S. Trout <mst@shadowcatsystems.co.uk>
CONTRIBUTORS
abraxxa: Alexander Hartmaier <alex_hartmaier@hotmail.com>
andyg: Andy Grundman <andy@hybridized.org>
ank: Andres Kievsky
ash: Ash Berlin <ash@cpan.org>
blblack: Brandon L. Black <blblack@gmail.com>
bluefeet: Aran Deltac <bluefeet@cpan.org>
captainL: Luke Saunders <luke.saunders@gmail.com>
castaway: Jess Robinson
claco: Christopher H. Laco
clkao: CL Kao
dkubb: Dan Kubb <dan.kubb-cpan@onautopilot.com>
draven: Marcus Ramberg <mramberg@cpan.org>
dwc: Daniel Westermann-Clark <danieltwc@cpan.org>
dyfrgi: Michael Leuchtenburg <michael@slashhome.org>
gphat: Cory G Watson <gphat@cpan.org>
jesper: Jesper Krogh
jguenther: Justin Guenther <jguenther@cpan.org>
konobi: Scott McWhirter
LTJake: Brian Cassidy <bricas@cpan.org>
ned: Neil de Carteret
nigel: Nigel Metheringham <nigelm@cpan.org>
ningu: David Kamholz <dkamholz@cpan.org>
Numa: Dan Sully <daniel@cpan.org>
paulm: Paul Makepeace
penguin: K J Cheetham
phaylon: Robert Sedlacek <phaylon@dunkelheit.at>
quicksilver: Jules Bean
sc_: Just Another Perl Hacker
scotty: Scotty Allen <scotty@scottyallen.com>
sszabo: Stephan Szabo <sszabo@bigpanda.com>
Todd Lipcon
typester: Daisuke Murase <typester@cpan.org>
victori: Victor Igumnov <victori@cpan.org>
wdh: Will Hawes
willert: Sebastian Willert <willert@cpan.org>
zamolxes: Bogdan Lucaciu <bogdan@wiz.ro>
LICENSE
You may distribute this code under the same terms as Perl itself.