X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass.pm;h=a6c290dc2451a38f78f6013d690d99d21b5a2dd2;hb=1e3ff0144580732bc73b4f8041ace7da5eae488c;hp=766976a204d00de0a4543d956d81b3a4ea60f7f9;hpb=f183eccd611133789a4f03bafde6a7e8979b26ff;p=dbsrgits%2FDBIx-Class-Historic.git diff --git a/lib/DBIx/Class.pm b/lib/DBIx/Class.pm index 766976a..a6c290d 100644 --- a/lib/DBIx/Class.pm +++ b/lib/DBIx/Class.pm @@ -17,7 +17,8 @@ $VERSION = '0.05999_04'; sub MODIFY_CODE_ATTRIBUTES { my ($class,$code,@attrs) = @_; - $class->mk_classdata('__attr_cache' => {}) unless $class->can('__attr_cache'); + $class->mk_classdata('__attr_cache' => {}) + unless $class->can('__attr_cache'); $class->__attr_cache->{$code} = [@attrs]; return (); } @@ -37,89 +38,99 @@ DBIx::Class - Extensible and flexible object <-> relational mapper. =head1 SYNOPSIS -DB/Main.pm: +Create a base schema class called DB/Main.pm: - package DB::Main; - use base qw/DBIx::Class::Schema/; - __PACKAGE__->load_classes(); + package DB::Main; + use base qw/DBIx::Class::Schema/; - 1; + __PACKAGE__->load_classes(); + 1; -DB/Main/Artist.pm: +Create a class that 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'); + package DB::Main::Artist; + use base qw/DBIx::Class/; - 1; + __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; -DB/Main/CD.pm: +A 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'); + package DB::Main::CD; + use base qw/DBIx::Class/; - 1; + __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'); -in application code: + 1; - my $ds = DB::Main->connect(@dbi_dsn); # DBI connect will happen on-demand +Then you can use these classes in your application's code: + # Connect to your database. + my $ds = DB::Main->connect(@dbi_dsn); + + # Query for all artists and put them in an array, + # or retrieve them as a result set object. my @all_artists = $ds->resultset('Artist')->all; + my $all_artists_rs = $ds->resultset('Artist'); + # Create a result set to search for artists. + # This does not query the DB. my $johns_rs = $ds->resultset('Artist')->search( - { 'name' => { 'like', 'John%' } }); # Doesn't query the db - - my @all_john_cds = $johns_rs->search_related('cds')->all; # Now it queries + # Build your WHERE using an SQL::Abstract structure: + { 'name' => { 'like', 'John%' } } + ); - my $first_john = $johns_rs->next; # Queries but only fetches one row so far + # This executes a joined query to get the cds + my @all_john_cds = $johns_rs->search_related('cds')->all; - my $first_john_cds_by_title_rs = $first_john->cds(undef, - { order_by => 'title' }); + # Queries but only fetches one row so far. + my $first_john = $johns_rs->next; - my $millenium_cds_rs = $ds->resultset('CD')->search( - { year => 2000 }, - { prefetch => 'artist' } ); + my $first_john_cds_by_title_rs = $first_john->cds( + undef, + { order_by => 'title' } + ); - my $cd = $millenium_cds_rs->next; # SELECT ... FROM cds JOIN artists ... + my $millennium_cds_rs = $ds->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 = $ds->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'); $ds->txn_do(sub { $new_cd->update }); # Runs the update in a transaction - $millenium_cds_rs->update({ year => 2002 }); # Single-query bulk update + $millennium_cds_rs->update({ year => 2002 }); # Single-query bulk update =head1 DESCRIPTION This is an SQL to OO mapper with an object API inspired by L -(and a compability layer as a springboard for porting) and a resultset API +(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 mant of the capabilities of the database as possible, +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 when it actually needs to in order to return something the user's +database when it actually needs to 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 @@ -133,10 +144,11 @@ 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 your best to maintain full backwards compatibility for published +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 now fairly substantial and several developer releases are -generally made to CPAN before the -current branch is merged back to trunk. +generally made to CPAN before the -current branch is merged back to trunk for +a major release. The community can be found via - @@ -152,7 +164,7 @@ The community can be found via - =over 4 -=item L - User's manual +=item L - user's manual =item L - DBIC Core Classes @@ -174,59 +186,59 @@ The community can be found via - =head1 AUTHOR -Matt S. Trout +mst: Matt S. Trout =head1 CONTRIBUTORS -Alexander Hartmaier +abraxxa: Alexander Hartmaier -Andy Grundman +andyg: Andy Grundman -Andres Kievsky +ank: Andres Kievsky -Brandon Black +blblack: Brandon Black -Brian Cassidy +LTJake: Brian Cassidy -Christopher H. Laco +claco: Christopher H. Laco -CL Kao +clkao: CL Kao -Daisuke Murase +typester: Daisuke Murase -Dan Kubb +dkubb: Dan Kubb -Dan Sully +Numa: Dan Sully -Daniel Westermann-Clark +dwc: Daniel Westermann-Clark -David Kamholz +ningu: David Kamholz -Jesper Krogh +jesper: Jesper Krogh -Jess Robinson +castaway: Jess Robinson -Jules Bean +quicksilver: Jules Bean -Justin Guenther +jguenther: Justin Guenther -Marcus Ramberg +draven: Marcus Ramberg -Nigel Metheringham +nigel: Nigel Metheringham -Paul Makepeace +paulm: Paul Makepeace -Robert Sedlacek +phaylon: Robert Sedlacek -sc_ of irc.perl.org#dbix-class +sc_: Just Another Perl Hacker -Scott McWhirter (konobi) +konobi: Scott McWhirter -Scotty Allen +scotty: Scotty Allen Todd Lipcon -Will Hawes +wdh: Will Hawes =head1 LICENSE