NAME
Tangram - Store pure objects in standard relational databases
DESCRIPTION
Tangram is an object-relational mapper.
It consists of an schema language that can be built around an object structure, or around an existing SQL schema (with some limitations). This schema language is rich enough to express such common RDBMS features as links, foreign keys, and link tables.
It also consists of a relational database storage engine, which based on the schema structure, will make Perl structures persist in a relational (SQL compliant) database. References to other objects (or collections, as represented with foreign keys and link tables) may be loaded using on demand references that `lazily' load data when it is needed.
Tangram has soundly engineered transaction support, without sacrificing excellent data caching abilities.
In short, it implements orthogonal object persistence.
Once your object are persistent, you can build query expressions to find them in terms of the schema language that you used to put them in. The schema data structure does not describe a data structure, it describes a data access pattern.
If you are looking for a tool that implements SQL abstraction only, you have probably missed the point (of this module, anyway), and a well-supported module like Class::DBI will likely suit your needs better.
Tangram is beginning to include preliminary support for aggregation functions, and currently supports grouping, summing and counting.
Tangram currently contains no support for database-side updates, but support is planned.
DOCUMENTATION INDEX
CONTENTS
- Tangram::Tour
-
The original "Guided Tour" of the features of Tangram, by the author of Tangram versions 1 through 2.04 (and a somewhat divergant version 3 ;-)), Jean-Louis LeRoy.
- Tangram::Springfield
-
The classes and schema used in the Guided Tour.
- Tangram::Storage
-
The main database handle class. Includes details on query syntax.
- Tangram::Cursor
-
Return an iterator that retrieves persistent objects in a result set one by one.
- Tangram::Schema
-
The Tangram schema structure - representing your data model so that Tangram can map it.
- Tangram::Relational::Mappings
-
An informative text on exactly how Object Relational Mapping is accomplished by the Tangram::Relational back-end, what the different styles of mapping are, and how each is selected.
- Tangram::Type
-
What Tangram types are available. This page is an index of other manual pages that express the data and relationship types available in Tangram.
- Tangram::Type::Extending
-
How to write your own custom types for Tangram.
- Tangram::Dialect
-
Database-specific extensions to Tangram, such as Tangram::mysql and Tangram::Sybase. These extensions only add functionality, and are not required for core operation of Tangram.
COMPATIBILITY
Tangram is known to run in the following environments, however, Tangram uses standard SQL and should be usable with any SQL-83 compliant database.
Note that some functions (e.g. transactions and subselects) may not be available in some environments. This is reported during the test suite.
Perl 5.6.1
Set::Object 1.04
DBI 1.14
DBD::mysql 2.0402
DBD::Oracle 1.06
DBD::Sybase 0.21
DBD::Pg 0.93
LICENSE & WARRANTY
You may use Tangram, free of charge, under the terms of the GPL.
You can obtain a commercial license for old (2.04 and earlier) versions of Tangram from Sound Object Logic, see http://www.soundobjectlogic.com/tangram/licenses.html.
TANGRAM COMES WITHOUT ANY WARRANTY OF ANY KIND.
SUPPORT
Please send bug reports directly to the Tangram 2 maintainer's mailing list <tangram-t2-maintainers@tangram-persistence.org>, and please CC: <bug-Tangram@rt.cpan.org> so your fault can be tracked accurately.
Whenever possible, include a short yet complete script demonstrating the problem. (read: if you want it fixed quicker, demonstrate it)
Questions of general interest should should be posted to the mailing list, but not sent to rt.cpan.org.
Commercial support for Tangram is available, see http://www.soundobjectlogic.com/tangram/support.html.
AUTHORS
Except where noted, all the code and documentation was written by Jean-Louis Leroy (jll@soundobjectlogic.com) and Sound Object Logic.
Sam Vilain <sam@vilain.net> is the current humble maintainer.
1 POD Error
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- Around line 94:
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