The following module was proposed for inclusion in the Module List:
modid: DBD::Trini
DSLIP: cdphl
description: Pure Perl DBMS
userid: MIKO (Miko O'Sullivan)
chapterid: 7 (Database_Interfaces)
communities:
UserFriendly
similar:
DBD::SQLite, DBD::Sprite
rationale:
NAME
DBD::Trini - Pure Perl DBMS
SYNOPSIS
Ugh, now matter howI try, the formatting of these synopses always
goes haywire when I post to register a namespace. Be kind, unwind.
#!/usr/local/bin/perl -w use strict; use DBD::Trini; my ($path,
$sql, $dbh, $sth, $i);
# directory where database is stored $path = 'mydb';
$sql = <<'(SQL)'; create table members member_pk VARCHAR(5),
name_first VARCHAR(25), name_last VARCHAR(25), notes MEMO (SQL)
# create the database $dbh = DBI->connect("dbi:Trini:$path", '',
'', {'create'=>1}); $dbh->do($sql) or die $DBI::errstr;
$dbh->commit();
# insert $sql = qq[ insert into members(member_pk, name_first,
name_last, notes) values(?,?,?,?) ]; $sth = $dbh->prepare($sql) or
die $DBI::errstr; $i=1;
$sth->execute( $i++, 'Starflower', 'Shanti', 'Totally cool chick')
or die $DBI::errstr; $sth->execute( $i++, 'Paul', 'Ruggerio',
'Dangerous with a spatula') or die $DBI::errstr; $sth->execute(
$i++, 'Mary', 'Edwin', 'Star Wars nut') or die $DBI::errstr;
$sth->execute( $i++, 'Ryan', 'Ragsdale', 'Loves his daughter') or
die $DBI::errstr; $sth->execute( $i++, 'Grady', 'Smith', 'Great
sculptor') or die $DBI::errstr;
# updates $sql = qq[ update members set name_first=? where
member_pk=2 ]; $sth = $dbh->prepare($sql) or die $DBI::errstr;
$sth->execute('Guido') or die $DBI::errstr;
# select $sql = qq[ select name_last || ',' ||| name_first as name
from members where member_pk=? ]; $sth = $dbh->prepare($sql) or die
$DBI::errstr; $sth->execute(2) or die $DBI::errstr;
while (my $row = $sth->fetchrow_hashref) { print $row->{'name'},
"\n" }
# delete $sql = 'delete from members where member_pk > ?'; $sth =
$dbh->prepare($sql); $sth->execute(3);
INSTALLATION
"Easy Installation" is one of Trini's central goals. Just copy
Trini.pm into the DBD/ directory of one of your library trees.
Or you can do the traditional routine:
perl Makefile.PL make make test make install
You will also need to install the following modules which are also
Pure Perl, are just as easy to install, and are on CPAN:
Data::Taxi SQL::YASP
Finally, you'll need to install the DBI module itself, which may be
anywhere from extremely easy (it's included in later distributions
of Perl 5) to painfully difficult, depending on your skill level. Be
sure to check out the notes in DBI about the the Pure Perl version
of DBI if you find it difficult to install DBI.
DESCRIPTION
Trini (pronounced "TRINN-EE") is a Pure Perl DBMS. Some highlights
of the eventual product:
- Commit/rollback segments
- Journaled data writing for automatic crash recovery
- All data stored in a single data file
- Open architecture for data type definitions (i.e., create your
own types of database fields)
- Enforcement of referential integrity
- Triggers
- Constraints
- Entirely written in the grooviest programming language there is
SO, DO THE WORLD REALLY NEED ANOTHER DBMS?
The creation of "yet another DBMS" requires some justification.
After all, there are already several excellent open source DBMS
packages, notably MySQL and PostGreSql.
And yet, despite the availability of those programs, Perl hackers
around the world continue to store data in Unix DB tables, flat
files, and other file-based data structures. The difficulty in using
those data storage techniques seems less daunting than the
difficulty of installing, starting, and connecting to a true DBMS
package.
The problem, I believe, is a simple question of paradigm confusion.
Programmers want to understand how and where their data is being
stored. They want to have a file where they can see the data, and
they want to be able to install a simple package quickly and begin
using it without spending a long time reading through installation
guides.
Finally, for those of us who prefer Perl to any other language,
there is a need for a DBMS that lets us join in the fun of hacking
the code.
Trini was created to fill this niche. The entirety of Trini's code
is contained in a half dozen Pure Perl modules, all of which can be
installed either through the traditional make/make test/make install
dance, or by simply copying them into your @INC library. The data is
stored in a single data file. Trini provides a rich (and extensible)
set of SQL operators and commands, compliments of SQL::YASP. Trini
provides commit/rollback segments, and automatic crash recovery,
both compliments of FileHandle::Rollback. Trini also provides an
extensible field type API, so that if the built-in data types
(NUMBER, VARCHAR, MEMO, others) don't suit you, you can define your
own.
Trini is still in its early stages. I've defined a data structure.
It can do basic database definition, inserts, deletes, updates and
selects. I invite all interested parties to join in the fun.
SIMILAR MODULES
Trini is hardly the first Pure Perl database manager. However, to
my knowledge none of them provide the same set of features as listed
above, though many provide some of those features. Some similar
modules are:
DBD::Sprite
Sprite is a popular Pure Perl DBMS with many of the features listed
above. AFAIK, however, it does not support the following features,
and given how Sprite stores data, it is not likely to do so in the
near future:
- Cannot store undefs, only stores nulls as empty strings.
- Does not have auomatic crash recovery
- Does not have extensible datatype API
- Does not support extensible SQL function and operator definitions
- Does not handle "memo" (i.e. strings of arbitrary length) fields
- Does not have indexing to speed up queries.
- Sprite does not bill itself as a production-worthy DBMS. Trini
will.
BTW, I always get yelled at when I attempt to list the differences
in modules. Jim, I apologize in advance if this list isn't quite
right. Drop me a line and I'll fix it. :-)
Sprite does support user-ids and passwords, which is a nice
feature. Trini doesn't support that feature, and for now I don't
plan to do so.
DBD::SQLite
DBD::SQLite is a very powerful local-file DBMS. It accomplishes
many of the same objectives as Trini. Is not Pure Perl. Obviously a
much more mature package than Trini, you should definitely look at
SQLite if you need to get going on a local-file project immediately.
A NOTE ABOUT THE STATE OF TRINI
This is an early release of Trini. In the spirit of Eric Raymond's
motto "Release Early, Release Often" I am releasing Trini before it
is a fully working module, or indeed before it is properly
documented. This version does some very basic databasing operations.
It allows you to create a database, insert, update, select, and
delete records. It supports two data types: varchar and memo. See
demo.pl for a basic walk through of Trini's current features.
A few things this module does NOT support are: modifying the
structure of a database, data integrity checks, file locking,
rollback segments, and automatic crash recovery. All of those
features are planned. Indeed, Trini was designed with those features
in mind.
See the TO DO section below for a more detailed list of planned
features.
AUTHOR Miko O'Sullivan [EMAIL PROTECTED]
VERSION Version 0.01 July 15, 2003 Initial release
enteredby: MIKO (Miko O'Sullivan)
enteredon: Tue Jul 15 07:12:53 2003 GMT
The resulting entry would be:
DBD::
::Trini cdphl Pure Perl DBMS MIKO
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