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 update

DESCRIPTION
    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-class

WHERE 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

    blblack: Brandon L. Black <blblack@gmail.com>

    bluefeet: Aran Deltac <bluefeet@cpan.org>

    LTJake: Brian Cassidy <bricas@cpan.org>

    claco: Christopher H. Laco

    clkao: CL Kao

    typester: Daisuke Murase <typester@cpan.org>

    dkubb: Dan Kubb <dan.kubb-cpan@onautopilot.com>

    Numa: Dan Sully <daniel@cpan.org>

    dwc: Daniel Westermann-Clark <danieltwc@cpan.org>

    ningu: David Kamholz <dkamholz@cpan.org>

    jesper: Jesper Krogh

    castaway: Jess Robinson

    quicksilver: Jules Bean

    jguenther: Justin Guenther <jguenther@cpan.org>

    captainL: Luke Saunders <luke.saunders@gmail.com>

    draven: Marcus Ramberg <mramberg@cpan.org>

    nigel: Nigel Metheringham <nigelm@cpan.org>

    paulm: Paul Makepeace

    phaylon: Robert Sedlacek <phaylon@dunkelheit.at>

    sc_: Just Another Perl Hacker

    konobi: Scott McWhirter

    scotty: Scotty Allen <scotty@scottyallen.com>

    sszabo: Stephan Szabo <sszabo@bigpanda.com>

    zamolxes: Bogdan Lucaciu <bogdan@wiz.ro>

    Todd Lipcon

    wdh: Will Hawes

    gphat: Cory G Watson <gphat@cpan.org>

    dyfrgi: Michael Leuchtenmurg <michael@slashhome.org>

LICENSE
    You may distribute this code under the same terms as Perl itself.

