Matthew Simon Cavalletto

NAME

DBIx::SQLEngine::Docs::ReadMe - Welcome to DBIx::SQLEngine

ABSTRACT

The DBIx::SQLEngine class provides an extended interface for the DBI database framework. Each SQLEngine object is a wrapper around a DBI database handle, adding methods that support ad-hoc SQL generation and query execution in a single call. Dynamic subclassing based on database server type enables cross-platform portability.

INTRODUCTION

DBIx::SQLEngine is the latest generation of a toolkit used by the authors for several years to develop business data applications and object-relational mapping toolkits. Its goal is to simplify dynamic query execution with the following capabilities:

  • High-Level Interface: Standard query operations are handled by a single method call each. Error handling is standardized, and routine annoyances like timed-out connections are retried automatically.

  • Data-Driven SQL: Ad-hoc generation of SQL statements from Perl data structures in a variety of formats; simple hash and array references are flexibly converted to form clauses in standard SQL query syntax.

  • Full DBI Access: Accepts arbitrary SQL queries with placeholder parameters to be passed through, and delegates any unknown method calls to the wrapped database handle, allowing access to the entire DBI API for cases when high-level interfaces are insufficient

  • Portability Subclasses: Uses dynamic subclassing to allow platform-specific support for driver idiosyncrasies and DBMS workarounds. This release includes subclasses for connections to MySQL, PostgreSQL, Oracle, and Microsoft SQL servers, as well as for the standalone SQLite, AnyData, and CSV packages.

  • Named Definitions: Enables pre-registration of a collection of names for sets of connection parameters, and a collection of of names for queries in either data-driven or plain-SQL formats. The definitions may include placeholders to be replaced by additional values at run-time.

  • Object Mapping: An optional layer provides classes for Record, Table and Column objects which fetch and store information from a SQLEngine. The Schema objects call methods on a SQLEngine to fetch and store data, while the Record classes create new subclasses to correspond to rows in a particular table.

DISTRIBUTION AND INSTALLATION

Version

This version is a routine release of DBIx::SQLEngine intended for public use.

This module's proposed CPAN registration should read:

  Name            DSLIP  Description
  --------------  -----  ---------------------------------------------
  DBIx::
  ::SQLEngine     Rdpop  Extends DBI with high-level operations

Prerequisites

This package requires these other modules and libraries:

  DBI                           1.0
  DBIx::AnyDBD                  2.0
  Class::MakeMethods            1.006

You must also have at least one working DBD module installed.

If you run into trouble, check that your DBI and DBD modules are up-to-date; in particular, if you are using DBD::CSV or DBD::AnyData, make sure you have upgraded to SQL::Statement 1.0 or later.

Installation

You should be able to install this module using the CPAN shell interface:

  perl -MCPAN -e 'install DBIx::SQLEngine'

In order for the test to succeed, you must also have at least one working DBD module installed, and must provide a DSN to which the script can connect with permissions to create tables.

Alternately, you may retrieve this package from CPAN or from the author's site:

  • http://search.cpan.org/~evo/

  • http://www.cpan.org/modules/by-authors/id/E/EV/EVO

  • http://www.evoscript.org/DBIx-SQLEngine/

After downloading the distribution, follow the normal procedure to unpack and install it, using the commands shown below or their local equivalents on your system:

  tar xzf DBIx-SQLEngine-*.tar.gz
  cd DBIx-SQLEngine-*
  perl Makefile.PL
  make test && sudo make install

Furthermore, thanks to the kind generosity of other members of the Perl community, this distribution is also available repackaged in the FreeBSD "ports" and Linux RPM formats. This may simplify installation for some users, but be aware that these alternate distributions may lag a few versions behind the latest release on CPAN.

  • http://www.freebsd.org/cgi/ports.cgi?query=DBIx-SQLEngine

  • http://www.rpmfind.net/linux/rpm2html/search.php?query=perl-DBIx-SQLEngine

Tested Platforms

This release has been tested succesfully on the following platforms:

  5.6.1 on darwin

You may also review the current test results from CPAN-Testers:

  • http://testers.cpan.org/show/DBIx-SQLEngine.html

BUGS AND SUPPORT

Known Problems

Many types of database servers are not yet supported.

Database driver/server combinations that do not support placeholders will fail. (http://groups.google.com/groups?selm=dftza.3519%24ol.117790%40news.chello.at)

See DBIx::SQLEngine::ToDo for additional bugs and missing features.

Release Status

This module has been used in a variety of production systems and has been available on CPAN for over a year, with several other distributions dependant on it, so it would be fair to say that it is fully released.

However, while the commonly-used portions are well tested, some of the more obscure combinations of options are less so, and new bug reports do trickle in occasionally. If you do encounter any problems, please inform the author and I'll endeavor to patch them promptly.

Additional features have been outlined for future development, but the intent is support these by adding more options to the declaration interface, while maintaining backward compatibility.

Support

If you have questions or feedback about this module, please feel free to contact the author at the below address. Although there is no formal support program, I do attempt to answer email promptly.

I would be particularly interested in any suggestions towards improving the documentation, correcting any Perl-version or platform dependencies, as well as general feedback and suggested additions.

Bug reports that contain a failing test case are greatly appreciated, and suggested patches will be promptly considered for inclusion in future releases.

To report bugs via the CPAN web tracking system, go to http://rt.cpan.org/NoAuth/Bugs.html?Dist=DBIx-SQLEngine or send mail to Dist=DBIx-SQLEngine#rt.cpan.org, replacing the # with @.

Community

If you've found this module useful or have feedback about your experience with it, consider sharing your opinion with other Perl users by posting your comment to CPAN's ratings system:

  • http://cpanratings.perl.org/rate/?distribution=DBIx-SQLEngine

For more general discussion, you may wish to post a message on PerlMonks or the comp.lang.perl.misc newsgroup:

  • http://www.perlmonks.org/index.pl?node=Seekers%20of%20Perl%20Wisdom

  • http://groups.google.com/groups?group=comp.lang.perl.misc

There have been a few small discussions of this module on PerlMonks and Usenet in the past:

  • http://groups.google.com/groups?q=dbix+sqlengine+-ports&scoring=d

  • http://perlmonks.org/index.pl?node_id=3989&BIT=sqlengine&go=Search

SEE ALSO

See DBIx::SQLEngine for interface documentation.

See DBIx::SQLEngine::Docs::Changes for revision history.

See DBIx::SQLEngine::Docs::Related for notes on related modules.

CREDITS AND COPYRIGHT

Author

Developed by Matthew Simon Cavalletto at Evolution Softworks.

You may contact the author directly at evo@cpan.org or simonm@cavalletto.org. More free Perl software is available at www.evoscript.org.

Contributors

Many thanks to the kind people who have contributed code and other feedback:

  Eric Schneider, Evolution Online Systems
  E. J. Evans, Evolution Online Systems
  Matthew Sheahan, Evolution Online Systems
  Eduardo Iturrate, Evolution Online Systems
  Ron Savage
  Christian Glahn, Innsbruck University
  Michael Kroll, Innsbruck University

Source Material

Inspiration, tricks, and bits of useful code were mined from these CPAN modules:

  Alzabo by Dave Rolsky 
  DBIx::AnyDBD by Matt Sergeant 
  DBIx::Compat by G. Richter
  DBIx::Datasource by Ivan Kohler 
  DBIx::Renderer by Marcel Grunauer 

Copyright 2001, 2002, 2003, 2004 Matthew Cavalletto.

Portions copyright 1998, 1999, 2000, 2001 Evolution Online Systems, Inc.

Portions copyright 2002 ZID, Innsbruck University (Austria).

Portions of the documentation are copyright 2003 Ron Savage.

License

You may use, modify, and distribute this software under the same terms as Perl.