From: Matt S Trout Date: Tue, 21 Mar 2006 04:57:00 +0000 (+0000) Subject: Doc updates in DBIx/Class.pm X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=f183eccd611133789a4f03bafde6a7e8979b26ff;p=dbsrgits%2FDBIx-Class-Historic.git Doc updates in DBIx/Class.pm --- diff --git a/lib/DBIx/Class.pm b/lib/DBIx/Class.pm index f59fc22..766976a 100644 --- a/lib/DBIx/Class.pm +++ b/lib/DBIx/Class.pm @@ -37,79 +37,132 @@ DBIx::Class - Extensible and flexible object <-> relational mapper. =head1 SYNOPSIS -=head1 DESCRIPTION +DB/Main.pm: -This is an SQL to OO mapper, inspired by the L framework, -and meant to support compability with it, while restructuring the -internals and making it possible to support some new features like -self-joins, distinct, group bys and more. + package DB::Main; + use base qw/DBIx::Class::Schema/; + __PACKAGE__->load_classes(); -This project is still at an early stage, so the maintainers don't make -any absolute promise that full backwards-compatibility will be supported; -however, if we can without compromising the improvements we're trying to -make, we will, and any non-compatible changes will merit a full justification -on the mailing list and a CPAN developer release for people to test against. + 1; -The community can be found via - - Mailing list: http://lists.rawmode.org/mailman/listinfo/dbix-class/ +DB/Main/Artist.pm: - SVN: http://dev.catalyst.perl.org/repos/bast/trunk/DBIx-Class/ + 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'); - Wiki: http://dbix-class.shadowcatsystems.co.uk/ + 1; - IRC: irc.perl.org#dbix-class -=head1 QUICKSTART +DB/Main/CD.pm: -If you're using L, and want an easy and fast way of migrating to -DBIx::Class, take a look at L. + 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'); -There are two ways of using DBIx::Class, the "simple" way and the "schema" way. -The "simple" way of using DBIx::Class needs less classes than the "schema" -way but doesn't give you the ability to easily use different database connections. + 1; -Some examples where different database connections are useful are: +in application code: -different users with different rights -different databases with the same schema. + my $ds = DB::Main->connect(@dbi_dsn); # DBI connect will happen on-demand -=head2 Simple + my @all_artists = $ds->resultset('Artist')->all; -First you need to create a base class which all other classes will inherit from. -See L for information on how to do this. + my $johns_rs = $ds->resultset('Artist')->search( + { 'name' => { 'like', 'John%' } }); # Doesn't query the db -Then you need to create a class for every table you want to use with DBIx::Class. -See L for information on how to do this. + my @all_john_cds = $johns_rs->search_related('cds')->all; # Now it queries -=head2 Schema + my $first_john = $johns_rs->next; # Queries but only fetches one row so far -With this approach, the table classes inherit directly from DBIx::Class::Core, -although it might be a good idea to create a "parent" class for all table -classes that inherits from DBIx::Class::Core and adds additional methods -needed by all table classes, e.g. reading a config file or loading auto primary -key support. + my $first_john_cds_by_title_rs = $first_john->cds(undef, + { order_by => 'title' }); -Look at L for information on how to do this. + my $millenium_cds_rs = $ds->resultset('CD')->search( + { year => 2000 }, + { prefetch => 'artist' } ); -If you need more help, check out the introduction in the -manual below. + my $cd = $millenium_cds_rs->next; # SELECT ... FROM cds JOIN artists ... -=head1 SEE ALSO + my $cd_artist_name = $cd->artist->name; # Already has the data so no query -=over 4 + my $new_cd = $ds->resultset('CD')->new({ title => 'Spoon' }); -=item L - DBIC Core Classes + $new_cd->artist($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 + +=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 +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, +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 +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 your 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. + +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 + +=head1 WHERE TO GO NEXT + +=over 4 =item L - User's manual +=item L - DBIC Core Classes + =item L - L Compat layer -=item L +=item L - schema and connection container -=item L +=item L - tables and table-like things -=item L +=item L - encapsulates a query and its results =item L - row-level methods