Ubuntu Manpage: DBIx::Class - Extensible and flexible object <-> relational mapper.


       DBIx::Class - Extensible and flexible object <-> relational mapper.


       See DBIx::Class::Manual::DocMap for an overview of the exhaustive documentation.  To get the most out of
       DBIx::Class with the least confusion it is strongly recommended to read (at the very least) the Manuals
       in the order presented there.


       Due to the complexity of its problem domain, DBIx::Class is a relatively complex framework. After you
       start using DBIx::Class questions will inevitably arise. If you are stuck with a problem or have doubts
       about a particular approach do not hesitate to contact the community with your questions. The list below
       is sorted by "fastest response time":

       •   IRC: irc.perl.org#dbix-class

       •   Mailing list: <http://lists.scsys.co.uk/mailman/listinfo/dbix-class>

       •   RT Bug Tracker: <https://rt.cpan.org/NoAuth/Bugs.html?Dist=DBIx-Class>

       •   Twitter: <https://www.twitter.com/dbix_class>

       •   Web Site: <http://www.dbix-class.org/>


   Schema classes preparation
       Create a schema class called MyApp/Schema.pm:

         package MyApp::Schema;
         use base qw/DBIx::Class::Schema/;

         __PACKAGE__->load_namespaces();

         1;

       Create a result class to represent artists, who have many CDs, in MyApp/Schema/Result/Artist.pm:

       See DBIx::Class::ResultSource for docs on defining result classes.

         package MyApp::Schema::Result::Artist;
         use base qw/DBIx::Class::Core/;

         __PACKAGE__->table('artist');
         __PACKAGE__->add_columns(qw/ artistid name /);
         __PACKAGE__->set_primary_key('artistid');
         __PACKAGE__->has_many(cds => 'MyApp::Schema::Result::CD', 'artistid');

         1;

       A result class to represent a CD, which belongs to an artist, in MyApp/Schema/Result/CD.pm:

         package MyApp::Schema::Result::CD;
         use base qw/DBIx::Class::Core/;

         __PACKAGE__->load_components(qw/InflateColumn::DateTime/);
         __PACKAGE__->table('cd');
         __PACKAGE__->add_columns(qw/ cdid artistid title year /);
         __PACKAGE__->set_primary_key('cdid');
         __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Result::Artist', 'artistid');

         1;

   API usage
       Then you can use these classes in your application's code:

         # Connect to your database.
         use MyApp::Schema;
         my $schema = MyApp::Schema->connect($dbi_dsn, $user, $pass, \%dbi_params);

         # Query for all artists and put them in an array,
         # or retrieve them as a result set object.
         # $schema->resultset returns a DBIx::Class::ResultSet
         my @all_artists = $schema->resultset('Artist')->all;
         my $all_artists_rs = $schema->resultset('Artist');

         # Output all artists names
         # $artist here is a DBIx::Class::Row, which has accessors
         # for all its columns. Rows are also subclasses of your Result class.
         foreach $artist (@all_artists) {
           print $artist->name, "\n";
         }

         # 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 the next available 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 data
         # 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 2nd query

         # new() makes a Result object but doesnt insert it into the DB.
         # create() is the same as new() then insert().
         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

         # change the year of all the millennium CDs at once
         $millennium_cds_rs->update({ year => 2002 });


       This is an SQL to OO mapper with an object API inspired by Class::DBI (with 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", "ORDER 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 large new features may be marked experimental - such
       APIs are still usable but may have edge bugs.  Failing test cases are always welcome and point releases
       are put out rapidly as bugs are found and fixed.

       We do our best to maintain full backwards compatibility for published APIs, since DBIx::Class is used in
       production in many organisations, and even backwards incompatible changes to non-published APIs will be
       fixed if they're reported and doing so doesn't cost the codebase anything.

       The test suite is quite substantial, and several developer releases are generally made to CPAN before the
       branch for the next release is merged back to trunk for a major release.


       Contributions are always welcome, in all usable forms (we especially welcome documentation improvements).
       The delivery methods include git- or unified-diff formatted patches, GitHub pull requests, or plain bug
       reports either via RT or the Mailing list. Contributors are generally granted full access to the official
       repository after their first patch passes successful review.

       This project is maintained in a git repository. The code and related tools are accessible at the
       following locations:

       •   Official repo: <git://git.shadowcat.co.uk/dbsrgits/DBIx-Class.git>

       •   Official gitweb: <http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits/DBIx-Class.git>

       •   GitHub mirror: <https://github.com/dbsrgits/DBIx-Class>

       •   Authorized committers: <ssh://dbsrgits@git.shadowcat.co.uk/DBIx-Class.git>

       •   Travis-CI log: <https://travis-ci.org/dbsrgits/dbix-class/builds>


       mst: Matt S. Trout <mst@shadowcatsystems.co.uk>

       (I mostly consider myself "project founder" these days but the AUTHOR heading is traditional :)


       abraxxa: Alexander Hartmaier <abraxxa@cpan.org>

       acca: Alexander Kuznetsov <acca@cpan.org>

       aherzog: Adam Herzog <adam@herzogdesigns.com>

       Alexander Keusch <cpan@keusch.at>

       alexrj: Alessandro Ranellucci <aar@cpan.org>

       alnewkirk: Al Newkirk <we@ana.im>

       amiri: Amiri Barksdale <amiri@metalabel.com>

       amoore: Andrew Moore <amoore@cpan.org>

       andrewalker: Andre Walker <andre@andrewalker.net>

       andyg: Andy Grundman <andy@hybridized.org>

       ank: Andres Kievsky

       arc: Aaron Crane <arc@cpan.org>

       arcanez: Justin Hunter <justin.d.hunter@gmail.com>

       ash: Ash Berlin <ash@cpan.org>

       bert: Norbert Csongradi <bert@cpan.org>

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

       bluefeet: Aran Deltac <bluefeet@cpan.org>

       bphillips: Brian Phillips <bphillips@cpan.org>

       boghead: Bryan Beeley <cpan@beeley.org>

       brd: Brad Davis <brd@FreeBSD.org>

       bricas: Brian Cassidy <bricas@cpan.org>

       brunov: Bruno Vecchi <vecchi.b@gmail.com>

       caelum: Rafael Kitover <rkitover@cpan.org>

       caldrin: Maik Hentsche <maik.hentsche@amd.com>

       castaway: Jess Robinson

       claco: Christopher H. Laco

       clkao: CL Kao

       da5id: David Jack Olrik <djo@cpan.org>

       dariusj: Darius Jokilehto <dariusjokilehto@yahoo.co.uk>

       davewood: David Schmidt <davewood@gmx.at>

       daxim: Lars DXXXXXX XXX <daxim@cpan.org>

       debolaz: Anders Nor Berle <berle@cpan.org>

       dew: Dan Thomas <dan@godders.org>

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

       dnm: Justin Wheeler <jwheeler@datademons.com>

       dpetrov: Dimitar Petrov <mitakaa@gmail.com>

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

       dyfrgi: Michael Leuchtenburg <michael@slashhome.org>

       edenc: Eden Cardim <edencardim@gmail.com>

       felliott: Fitz Elliott <fitz.elliott@gmail.com>

       freetime: Bill Moseley <moseley@hank.org>

       frew: Arthur Axel "fREW" Schmidt <frioux@gmail.com>

       goraxe: Gordon Irving <goraxe@cpan.org>

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

       Grant Street Group <http://www.grantstreet.com/>

       groditi: Guillermo Roditi <groditi@cpan.org>

       Haarg: Graham Knop <haarg@haarg.org>

       hobbs: Andrew Rodland <arodland@cpan.org>

       ilmari: Dagfinn Ilmari Mannsaaker <ilmari@ilmari.org>

       initself: Mike Baas <mike@initselftech.com>

       ironcamel: Naveed Massjouni <naveedm9@gmail.com>

       jawnsy: Jonathan Yu <jawnsy@cpan.org>

       jasonmay: Jason May <jason.a.may@gmail.com>

       jesper: Jesper Krogh

       jgoulah: John Goulah <jgoulah@cpan.org>

       jguenther: Justin Guenther <jguenther@cpan.org>

       jhannah: Jay Hannah <jay@jays.net>

       jmac: Jason McIntosh <jmac@appleseed-sc.com>

       jnapiorkowski: John Napiorkowski <jjn1056@yahoo.com>

       jon: Jon Schutz <jjschutz@cpan.org>

       jshirley: J. Shirley <jshirley@gmail.com>

       kaare: Kaare Rasmussen

       konobi: Scott McWhirter

       littlesavage: Alexey Illarionov <littlesavage@orionet.ru>

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

       marcus: Marcus Ramberg <mramberg@cpan.org>

       mattlaw: Matt Lawrence

       mattp: Matt Phillips <mattp@cpan.org>

       michaelr: Michael Reddick <michael.reddick@gmail.com>

       milki: Jonathan Chu <milki@rescomp.berkeley.edu>

       mithaldu: Christian Walde <walde.christian@gmail.com>

       mjemmeson: Michael Jemmeson <michael.jemmeson@gmail.com>

       mstratman: Mark A. Stratman <stratman@gmail.com>

       ned: Neil de Carteret

       nigel: Nigel Metheringham <nigelm@cpan.org>

       ningu: David Kamholz <dkamholz@cpan.org>

       Nniuq: Ron "Quinn" Straight" <quinnfazigu@gmail.org>

       norbi: Norbert Buchmuller <norbi@nix.hu>

       nuba: Nuba Princigalli <nuba@cpan.org>

       Numa: Dan Sully <daniel@cpan.org>

       ovid: Curtis "Ovid" Poe <ovid@cpan.org>

       oyse: Oystein Torget <oystein.torget@dnv.com>

       paulm: Paul Makepeace

       penguin: K J Cheetham

       perigrin: Chris Prather <chris@prather.org>

       peter: Peter Collingbourne <peter@pcc.me.uk>

       Peter Valdemar Morch <peter@morch.com>

       phaylon: Robert Sedlacek <phaylon@dunkelheit.at>

       plu: Johannes Plunien <plu@cpan.org>

       Possum: Daniel LeWarne <possum@cpan.org>

       quicksilver: Jules Bean

       rafl: Florian Ragwitz <rafl@debian.org>

       rainboxx: Matthias Dietrich <perl@rb.ly>

       rbo: Robert Bohne <rbo@cpan.org>

       rbuels: Robert Buels <rmb32@cornell.edu>

       rdj: Ryan D Johnson <ryan@innerfence.com>

       ribasushi: Peter Rabbitson <ribasushi@cpan.org>

       rjbs: Ricardo Signes <rjbs@cpan.org>

       robkinyon: Rob Kinyon <rkinyon@cpan.org>

       Robert Olson <bob@rdolson.org>

       moltar: Roman Filippov <romanf@cpan.org>

       Sadrak: Felix Antonius Wilhelm Ostmann <sadrak@cpan.org>

       sc_: Just Another Perl Hacker

       scotty: Scotty Allen <scotty@scottyallen.com>

       semifor: Marc Mims <marc@questright.com>

       SineSwiper: Brendan Byrd <bbyrd@cpan.org>

       solomon: Jared Johnson <jaredj@nmgi.com>

       spb: Stephen Bennett <stephen@freenode.net>

       Squeeks <squeek@cpan.org>

       sszabo: Stephan Szabo <sszabo@bigpanda.com>

       talexb: Alex Beamish <talexb@gmail.com>

       tamias: Ronald J Kimball <rjk@tamias.net>

       teejay : Aaron Trevena <teejay@cpan.org>

       Todd Lipcon

       Tom Hukins

       tonvoon: Ton Voon <tonvoon@cpan.org>

       triode: Pete Gamache <gamache@cpan.org>

       typester: Daisuke Murase <typester@cpan.org>

       victori: Victor Igumnov <victori@cpan.org>

       wdh: Will Hawes

       wesm: Wes Malone <wes@mitsi.com>

       willert: Sebastian Willert <willert@cpan.org>

       wreis: Wallace Reis <wreis@cpan.org>

       xenoterracide: Caleb Cushing <xenoterracide@gmail.com>

       yrlnry: Mark Jason Dominus <mjd@plover.com>

       zamolxes: Bogdan Lucaciu <bogdan@wiz.ro>


       Copyright (c) 2005 - 2011 the DBIx::Class "AUTHOR" and "CONTRIBUTORS" as listed above.


       This library is free software and may be distributed under the same terms as perl itself.

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