UR - rich declarative non-hierarchical transactional objects
This document describes UR version 0.6.
First create a Namespace class for your application, CdExample.pm
package CdExample; use UR; class CdExample { is => 'UR::Namespace' }; 1;
Next, define a data source representing your database, CdExample/DataSource/DB1.pm
package CdExample::DataSource::DB1; use CdExample; class CdExample::DataSource::DB1 { is => ['UR::DataSource::Mysql'], has_constant => [ server => { value => 'mysql.example.com' }, login => { value => 'mysqluser' }, auth => { value => 'mysqlpasswd' }, ] }; 1;
Create a class to represent artists, who have many CDs, in CdExample/Artist.pm
package CdExample::Artist; use CdExample; class CdExample::Artist { id_by => 'artist_id', has => [ name => { is => 'Text' }, cds => { is => 'CdExample::Cd', is_many => 1, reverse_as => 'artist' } ], data_source => 'CdExample::DataSource::DB1', table_name => 'ARTISTS', }; 1;
Create a class to represent CDs, in CdExample/Cd.pm
package CdExample::Cd; use CdExample; class CdExample::Cd { id_by => 'cd_id', has => [ artist => { is => 'CdExample::Artist', id_by => 'artist_id' }, title => { is => 'Text' }, year => { is => 'Integer' }, artist_name => { via => 'artist', to => 'name' }, ], data_source => 'CdExample::DataSource::DB1', table_name => 'CDS', }; 1;
You can then use these classes in your application code
# Enables auto-loading for modules in this Namespace use CdExample; # this would get back all Artist objects my @all_artists = CdExample::Artist->get(); # after the above, further requests would be cached # if that set were large though, you might want to iterate gradually: my $artist_iter = CdExample::Artist->create_iterator(); # Get the first object off of the iterator my $first_artist = $artist_iter->next(); # Get all the CDs published in 2007 my @cds_2007 = CdExample::Cd->get(year => 2007); # Get a list of Artist objects where the name starts with 'John' my @some_artists = CdExample::Artist->get( name => { operator => 'like', value => 'John%' } ); # Alternate syntax for non-equality operators my @same_some_artists = CdExample::Artist->get('name like' => 'John%'); # This will use a JOIN with the ARTISTS table internally to filter # the data in the database. @some_cds will contain CdExample::Cd objects. # As a side effect, related Artist objects will be loaded into the cache my @some_cds = CdExample::Cd->get(i year => '2001', artist_name => { operator => 'like', value => 'Bob%' } ); my @artists_for_some_cds = map { $_->artist } @some_cds; # This will use a join to prefetch Artist objects related to the # Cds that match the filter my @other_cds = CdExample::Cd->get( title => { operator => 'like', value => '%White%' }, -hints => ['artist'] ); my $other_artist_0 = $other_cds[0]->artist; # already loaded so no query # create() instantiates a new object in the cache, but does not save # it in the database. It will autogenerate its own cd_id my $new_cd = CdExample::Cd->create( title => 'Cool Album', year => 2009 ); # Assign it to an artist; fills in the artist_id field of $new_cd $first_artist->add_cd($new_cd); # Save all changes back to the database UR::Context->current->commit;
UR is a class framework and object/relational mapper for Perl. It starts with the familiar Perl meme of the blessed hash reference as the basis for object instances, and extends its capabilities with ORM (object-relational mapping) capabilities, object cache, in-memory transactions, more formal class definitions, metadata, documentation system, iterators, command line tools, etc.
UR can handle multiple column primary and foreign keys, SQL joins involving class inheritance and relationships, and does its best to avoid querying the database unless the requested data has not been loaded before. It has support for SQLite, Oracle, Mysql and Postgres databases, and the ability to use a text file as a table.
UR uses the same syntax to define non-persistent objects, and supports in-memory transactions for both.
UR::Manual::Overview - UR from Ten Thousand Feet
UR::Manual::Tutorial - Getting started with UR
UR::Manual::Presentation - Slides for a presentation on UR
UR::Manual::Cookbook - Recepies for getting stuff working
UR::Manual::Metadata - UR's metadata system
UR::Object::Type::Initializer - Defining classes
UR::Manual::UR - UR's command line tool
UR::Object - Pretty much everything is-a UR::Object
UR::Object::Type - Metadata class for Classes
UR::Object::Property - Metadata class for Properties
UR::Namespace - Manage packages and classes
UR::Context - Software transactions and More!
UR::DataSource - How and where to get data
UR uses several environment variables to do things like run with database commits disabled, dump SQL, control cache size, etc.
See UR::Env.
Class::Autouse Cwd Data::Dumper Date::Calc Date::Parse DBI File::Basename FindBin FreezeThaw Path::Class Scalar::Util Sub::Installer Sub::Name Sys::Hostname Text::Diff Time::HiRes XML::Simple
UR was built by the software development team at the Washington University Genome Center. Incarnations of it run laboratory automation and analysis systems for high-throughput genomics.
Scott Smith sakoht@cpan.org Orginal Architecture Anthony Brummett brummett@cpan.org Primary Development Craig Pohl Todd Hepler Ben Oberkfell Kevin Crouse Adam Dukes Indraniel Das Shin Leong Eddie Belter Ken Swanson Scott Abbott Alice Diec William Schroeder Eric Clark Shawn Leonard Lynn Carmichael Jason Walker Amy Hawkins Gabe Sanderson James Weible James Eldred Michael Kiwala Mark Johnson Kyung Kim Jon Schindler Justin Lolofie Chris Harris Jerome Peirick Ryan Richt John Osborne David Dooling
Copyright (C) 2002-2009 Washington University in St. Louis, MO.
This sofware is licensed under the same terms as Perl itself. See the LICENSE file in this distribution.
To install UR, copy and paste the appropriate command in to your terminal.
cpanm
cpanm UR
CPAN shell
perl -MCPAN -e shell install UR
For more information on module installation, please visit the detailed CPAN module installation guide.