DEVTYPE=port DRIVER=port 1 ˆl–ß=¿J*C]Šq@µq–®JbÑ¿Á …œm—ÿ_‹uÐb &=LV[(ÅÄ?÷ package DBI::DBD; # vim:ts=8:sw=4 use strict; use vars qw($VERSION); # set $VERSION early so we don't confuse PAUSE/CPAN etc # don't use Revision here because that's not in svn:keywords so that the # examples that use it below won't be messed up $VERSION = "12.015129"; # $Id: DBD.pm 15128 2012-02-04 20:51:39Z Tim $ # # Copyright (c) 1997-2006 Jonathan Leffler, Jochen Wiedmann, Steffen # Goeldner and Tim Bunce # # You may distribute under the terms of either the GNU General Public # License or the Artistic License, as specified in the Perl README file. =head1 NAME DBI::DBD - Perl DBI Database Driver Writer's Guide =head1 SYNOPSIS perldoc DBI::DBD =head2 Version and volatility This document is I a minimal draft which is in need of further work. Please read the B documentation first and fully. Then look at the implementation of some high-profile and regularly maintained drivers like DBD::Oracle, DBD::ODBC, DBD::Pg etc. (Those are no no particular order.) Then reread the B specification and the code of those drivers again as you're reading this. It'll help. Where this document and the driver code differ it's likely that the driver code is more correct, especially if multiple drivers do the same thing. This document is a patchwork of contributions from various authors. More contributions (preferably as patches) are very welcome. =head1 DESCRIPTION This document is primarily intended to help people writing new database drivers for the Perl Database Interface (Perl DBI). It may also help others interested in discovering why the internals of a B driver are written the way they are. This is a guide. Few (if any) of the statements in it are completely authoritative under all possible circumstances. This means you will need to use judgement in applying the guidelines in this document. If in I doubt at all, please do contact the I mailing list (details given below) where Tim Bunce and other driver authors can help. =head1 CREATING A NEW DRIVER The first rule for creating a new database driver for the Perl DBI is very simple: B There is usually a driver already available for the database you want to use, almost regardless of which database you choose. Very often, the database will provide an ODBC driver interface, so you can often use B to access the database. This is typically less convenient on a Unix box than on a Microsoft Windows box, but there are numerous options for ODBC driver managers on Unix too, and very often the ODBC driver is provided by the database supplier. Before deciding that you need to write a driver, do your homework to ensure that you are not wasting your energies. [As of December 2002, the consensus is that if you need an ODBC driver manager on Unix, then the unixODBC driver (available from L) is the way to go.] The second rule for creating a new database driver for the Perl DBI is also very simple: B Nevertheless, there are occasions when it is necessary to write a new driver, often to use a proprietary language or API to access the database more swiftly, or more comprehensively, than an ODBC driver can. Then you should read this document very carefully, but with a suitably sceptical eye. If there is something in here that does not make any sense, question it. You might be right that the information is bogus, but don't come to that conclusion too quickly. =head2 URLs and mailing lists The primary web-site for locating B software and information is http://dbi.perl.org/ There are two main and one auxiliary mailing lists for people working with B. The primary lists are I for general users of B and B drivers, and I mainly for B driver writers (don't join the I list unless you have a good reason). The auxiliary list is I for announcing new releases of B or B dri