NAME

       UR - rich declarative transactional objects

VERSION

       This document describes UR version 0.45

SYNOPSIS

           use UR;

           ## no database

           class Foo { is => 'Bar', has => [qw/prop1 prop2 prop3/] };

           $o1 = Foo->create(prop1 => 111, prop2 => 222, prop3 => 333);

           @o = Foo->get(prop2 => 222, prop1 => [101,111,121], 'prop3 between' => [200, 400]);
           # returns one object

           $o1->delete;

           @o = Foo->get(prop2 => 222, prop1 => [101,111,121], 'prop3 between' => [200, 400]);
           # returns zero objects

           @o = Foo->get(prop2 => 222, prop1 => [101,111,121], 'prop3 between' => [200, 400]);
           # returns one object again

           ## database

           class Animal {
               has => [
                   favorite_food => { is => 'Text', doc => "what's yummy?" },
               ],
               data_source => 'MyDB1',
               table_name => 'Animal'
           };

           class Cat {
               is => 'Animal',
               has => [
                   feet    => { is => 'Number', default_value => 4 },
                   fur     => { is => 'Text', valid_values => [qw/fluffy scruffy/] },
               ],
               data_source => 'MyDB1',
               table_name => 'Cat'
           };

           Cat->create(feet => 4, fur => 'fluffy', favorite_food => 'taters');

           @cats = Cat->get(favorite_food => ['taters','sea bass']);

           $c = $cats[0];

           print $c->feet,"\n";

           $c->fur('scruffy');

           UR::Context->commit();

DESCRIPTION

       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.

DOCUMENTATION

   Manuals
       ur - command line interface

       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

   Basic Entities
       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

QUICK TUTORIAL

       First create a Namespace class for your application, Music.pm:

           package Music;
           use UR;

           class Music {
               is => 'UR::Namespace'
           };

           1;

       Next, define a data source representing your database, Music/DataSource/DB1.pm

           package Music::DataSource::DB1;
           use Music;

           class Music::DataSource::DB1 {
               is => ['UR::DataSource::MySQL', 'UR::Singleton'],
               has_constant => [
                   server  => { value => 'database=music' },
                   owner   => { value => 'music' },
                   login   => { value => 'mysqluser' },
                   auth    => { value => 'mysqlpasswd' },
               ]
           };

           or to get something going quickly, SQLite has smart defaults...

           class Music::DataSource::DB1 {
               is => ['UR::DataSource::SQLite', 'UR::Singleton'],
           };

       Create a class to represent artists, who have many CDs, in Music/Artist.pm

           package Music::Artist;
           use Music;

           class Music::Artist {
               id_by => 'artist_id',
               has => [
                   name => { is => 'Text' },
                   cds  => { is => 'Music::Cd', is_many => 1, reverse_as => 'artist' }
               ],
               data_source => 'Music::DataSource::DB1',
               table_name => 'ARTIST',
           };

       Create a class to represent CDs, in Music/Cd.pm

           package Music::Cd;
           use Music;

           class Music::Cd {
               id_by => 'cd_id',
               has => [
                   artist => { is => 'Music::Artist', id_by => 'artist_id' },
                   title  => { is => 'Text' },
                   year   => { is => 'Integer' },
                   artist_name => { via => 'artist', to => 'name' },
               ],
               data_source => 'Music::DataSource::DB1',
               table_name => 'CD',
           };

       If the database does not exist, you can run this to generate the tables and columns from
       the classes you've written (very experimental):

         $ cd Music
         $ ur update schema

       If the database existed already, you could have done this to get it to write the last 2
       classes for you:

         $ cd Music;
         $ ur update classes

       Regardless, if the classes and database tables are present, you can then use these classes
       in your application code:

           # Using the namespace enables auto-loading of modules upon first attempt to call a method
           use Music;

           # This would get back all Artist objects:
           my @all_artists = Music::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 = Music::Artist->create_iterator();

           # Get the first object off of the iterator
           my $first_artist = $artist_iter->next();

           # Get all the CDs published in 2007 for the first artist
           my @cds_2007 = Music::Cd->get(year => 2007, artist => $first_artist);

           # Use non-equality operators:
           my @some_cds = Music::Cd->get(
               'year between' => ['2004','2009']
           );

           # This will use a JOIN with the ARTISTS table internally to filter
           # the data in the database.  @some_cds will contain Music::Cd objects.
           # As a side effect, related Artist objects will be loaded into the cache
           @some_cds = Music::Cd->get(
               year => '2007',
               'artist_name like' => 'Bob%'
           );

           # These values would be cached...
           my @artists_for_some_cds = map { $_->artist } @some_cds;

           # This will use a join to prefetch Artist objects related to the
           # objects that match the filter
           my @other_cds = Music::Cd->get(
               'title like' => '%White%',
               -hints => ['artist']
           );
           my $other_artist_0 = $other_cds[0]->artist;  # already loaded so no query

           # create() instantiates a new object in the current "context", but does not save
           # it in the database.  It will autogenerate its own cd_id:
           my $new_cd = Music::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 in the current transaction back to the database(s)
           # which are behind the changed objects.
           UR::Context->current->commit;

Environment Variables

       UR uses several environment variables to do things like run with database commits
       disabled, watching SQL queries run, examine query plans, and control cache size, etc.

       These make development and debugging fast and easy.

       See UR::Env for details.

DEPENDENCIES

       Class::Autouse Cwd Data::Dumper Date::Format DBI File::Basename FindBin FreezeThaw
       Path::Class Scalar::Util Sub::Installer Sub::Name Sys::Hostname Text::Diff Time::HiRes
       XML::Simple

AUTHORS

       UR was built by the software development team at the McDonnell Genome Institute at the
       Washington University School of Medicine (Richard K. Wilson, PI).

       Incarnations of it run laboratory automation and analysis systems for high-throughput
       genomics.

        Anthony Brummett   brummett@cpan.org
        Nathan Nutter
        Josh McMichael
        Eric Clark
        Ben Oberkfell
        Eddie Belter
        Feiyu Du
        Adam Dukes
        Brian Derickson
        Craig Pohl
        Gabe Sanderson
        Todd Hepler
        Jason Walker
        James Weible
        Indraniel Das
        Shin Leong
        Ken Swanson
        Scott Abbott
        Alice Diec
        William Schroeder
        Shawn Leonard
        Lynn Carmichael
        Amy Hawkins
        Michael Kiwala
        Kevin Crouse
        Mark Johnson
        Kyung Kim
        Jon Schindler
        Justin Lolofie
        Jerome Peirick
        Ryan Richt
        John Osborne
        Chris Harris
        Philip Kimmey
        Robert Long
        Travis Abbott
        Matthew Callaway
        James Eldred
        Scott Smith        sakoht@cpan.org
        David Dooling

LICENCE AND COPYRIGHT

       Copyright (C) 2002-2016 Washington University in St. Louis, MO.

       This software is licensed under the same terms as Perl itself.  See the LICENSE file in
       this distribution.