The Informix Zone - ruby

New Ruby/Informix Website

eherber — Tue, 01 Apr 2008 18:02:35 +0200

New Ruby/Informix Website

If you are an Informix fan - you probably are as you are visiting The Informix Zone - and you are looking for a powerful, easy to learn and robust programming language, take a deeper look at Ruby. Combined with the Ruby on Rails framework, Ruby is an extremely efficient language for developing web based applications. Applications that probably need a high performance OLTP cluster database like IDS.

Learn more about connecting IDS with Ruby on Gerardo Santana's new website:

http://ruby-informix.rubyforge.org

Ruby/Informix 0.6.0 released

santana — Wed, 29 Aug 2007 07:11:25 +0200

Ruby/Informix 0.6.0 released

There are two important additions in this release:

Test suite
Exception classes for Informix errors

Please read the following changelog for details.

Changelog:

0.6.0 08/28/2007
------------------
New features:

Test suite
Error, Warning, and AssertionFailure classes replace RuntimeError when raising exceptions.
Error class methods:
- message
- sql_code
- add_info
- []
- each
- to_s
- size, length

message and sql_code reference the first error message. Following
errors can be accessed through Error#[] as ExcInfo objects.

ExcInfo is a Struct with the following members:
- sql_code
- sql_state
- class_origin_val
- subclass_origin_val
- message
- server_name
- connection_name

See test/testcase.rb for a simple example of exception handling.
Informix.version returns the version of this extension
Database#do aliased as Database#execute
More documentation

Remarks:

Database#do is deprecated and will be removed in next versions. Use Database#execute or Database#immediate instead.
In case of Informix errors, RuntimeError objects are no longer raised.
Error, Warning and AssertionFailure objects are raised instead.

Acknowledgments:
I want to thank Edwin Fine (emofine at finecomputerconsultants dot com) who contributed all the functionality of this release.

--
Gerardo Santana

Ruby/Informix 0.5.1 released

santana — Tue, 14 Aug 2007 01:11:53 +0200

This is a maintenance release.

The code that interprets DATETIME columns had a bug.

Time objects were being instantiated with incorrect values when the original ones had leading zeroes and the DATETIME column was defined with the HOUR TO SECOND qualifier.

Thanks to Daniel Bush
for his report.

Home page: http://ruby-informix.rubyforge.org
Download from: http://rubyforge.org/projects/ruby-informix/

Addition from Eric:
Please also read this interesting summary from Guy Bowerman about enhancements in IDS 11 regarding the network protocol:

Ruby/Informix, and the Ruby Common client

Ruby/Informix 0.5.0 released

santana — Fri, 29 Dec 2006 17:23:25 +0100

Ruby/Informix is a Ruby extension for connecting to IBM Informix Dynamic Server, written in ESQL/C.

It is being developed and heavily tested on Solaris/SPARC. It has been reported to work on Linux, Windows and HP-UX.

There are four major enhancements in this release:

Use of BigDecimal for MONEY/DECIMAL columns
Resource management by means of blocks for statements, cursors and connnections
Support for SLOB status and storage characteristics information gathering
Thread safe

Along with bug fixes, more documentation and new handy methods.

Special thanks to Guy Bowerman, Jonathan Leffler and Logan Capaldo for their feedback and help.

Home page: http://ruby-informix.rubyforge.org
Download from: http://rubyforge.org/projects/ruby-informix/

Changelog:

0.5.0  12/27/2006
------------------
New features:
       * Easier to install
       * BigDecimal accepted for input parameters
       * BigDecimal used for instantiating DECIMAL and MONEY values
       * Cursor, Statement, Slob and Database accept an optional block that
         automatically frees resources after execution.
         Based on ideas and pseudo-code by
         Edwin Fine <emofine at finecomputerconsultants dot com> and me.
       * Database#slob shortcut for creating Slob objects.
       * Slob::Stat class implemented. Returned by Slob#stat, represents the
         SLOB status. Methods: atime, ctime, mtime, refcnt and size. Includes
         Comparable.
       * Slob new methods: <<, rewind, stat, pos, pos=, lock, unlock,
                           estbytes, extsz, flags, maxbytes, sbspace,
                           extsz=, flags=,
                           atime, ctime, mtime, refcnt and size
       * Thread safe

Remarks:
       * DECIMAL and MONEY columns are no longer returned as Float. BigDecimal
         is used instead.

Bugs fixed:
       * If there was an error reading (ifx_lo_read) an SLOB, memory
         allocated for the read buffer was not freed. Noticed by
         Edwin Fine <emofine at finecomputerconsultants dot com>
       * maxbytes option was ignored when creating an Slob object
       * Documentation for Slob mentioned an RDRW constant, but it actually
         is RDWR.

A gem for Informix

santana — Fri, 22 Dec 2006 22:32:22 +0100

Not long ago, around mid-2005, I was enchanted by the beauty of Ruby on Rails. Not much time passed until I found where the beauty came from.

My name is Gerardo Santana and I'm the author of the Ruby driver for Informix, the RDBMS that powers the largest database of employees (for a personnel management and payment system) and the largest database of students (for a student information system) in the state of Chiapas, at my work place.

Before deciding to write the Ruby driver, I tried the Perl driver first (Python was not an option since at the time it was in beta.) But after knowing and enjoying Ruby on Rails, I decided to rewrite one of our systems with it. Not having the ActiveRecord adapter for Informix, not even a native Ruby driver for Informix, drove me to give Informix not one, but two gems: Ruby/Informix and Rails/Informix.

And it has proved rewarding. Solving real problems in a fast, reliable and ejoyable way is priceless.

Fast, because it's using the ESQL/C interface as it was intended to be, instead of arbitrary DB APIs. Let the programmer unleash the full power of Informix.
Reliable, because it lets you write safer code that automatically and immediatly frees database resources after using them. No more resource leaks.
Enjoyable. Thank you Matz.

In the next posts I will provide examples of effective and efficient uses of the Ruby driver as well as interesting uses of ActiveRecord with Informix.

Talking with Perl, PHP, Python, Ruby to IDS

eherber — Sun, 19 Nov 2006 09:04:49 +0100

Creating a Powerful Mixture

This article describes the database interfaces of popular script languages like Perl, PHP, Python or Ruby which provide direct access to data stored in Informix Dynamic Server.

Powerful Script Languages
Powerful IDS Capabilities
Best of Breed
Database Abstraction Layer
IDS and Perl
IDS and PHP
IDS and Python
IDS and Ruby

Powerful Script Languages

Script languages like Perl, PHP, Python and Ruby are getting more and more popular. Beside rapid prototyping capabilities they also allow the development of complex software projects in a time-saving and efficient manner.

Powerful Informix Capabilities

Inormix Dynamic Server is a strategic data server inside the IBM Information Management Division that is well known for it's outstanding capabilities:

Impressive Transaction Performance
High Reliability and First Class Support
Rich, sophisticated Extensibility Features
Backward Compatibility and Painless Version Upgrades
Powerful Replication Solutions inside the DBMS Kernel
Hardware gentle, scalable Multithreading Architecture
Extremely low Administration Overhead

Script Languages + IDS = Powerful Mixture

Combining the advantages of Perl, PHP, Python or Ruby with IBM's cult database Informix Dynamic Server results in an extremly efficient software platform. A platform that is well primed for increasing data volumes and the most demanding high availability requirements.

Database Abstraction Layer

All four script languages offer a database abstraction layer which allows the programming of portable database applications:

The Informix specific implementations of those database abstraction layers are all programmed in Esql/C. In order to compile the driver you need beside a C compiler the free of charge Informix Client SDK software installed. The Client SDK can be downloaded from here:

Free Download of Client SDK

Perl has a long history and is still one of the most popular scripting languages available today. Beside the development of web based applications, Perl is heavily used in the area of system administration automation on Unix and Linux systems. Another prominent Perl area is the extraction and conversion of data due to it's outstanding text processing capabilities.

Perl provides a rich offering of additional modules for almost every task, just take a look at the Comprehensive Perl Archive Network (CPAN). The DBI (DataBase Interface) is the well established standard for accessing databases from Perl. It defines a set of abstract methods which are implemented by the underlaying DataBase Driver (DBD). The driver for accessing an Informix database is called DBD::Informix and it has been written by Jonathan Leffler, a superb Informix expert and architect of Informix@IBM. DBD::Informix is well-engineered and contains an excellent documentation.

Installation steps for DB-API DBD::Informix

Download DBD::Informix
gzcat <perl_ifx_archive> | tar xvf -
cd <perl_ifx_archive_dir>
perl Makefile.PL
make
make test
make install

Example Program

#!/usr/bin/perl

use warnings;
use strict;
use DBI;

# ------------------------------------
# open connection to database 'stores'
# ------------------------------------
my $dbh = DBI->connect
          (
             "DBI:Informix:stores",
             '',
             '',
             { PrintError => 0, RaiseError => 1, AutoCommit => 0 }
          );

# ----------------
# open transaction
# ----------------
$dbh->do("begin");

# --------------------------------------
# prepare and execute 'select' statement
# --------------------------------------
my $sth1 =$dbh->prepare("select code, sname from state");
$sth1->execute();

# --------------------------
# prepare 'delete' statement
# --------------------------
my $sth2 = $dbh->prepare("delete from state where code = ?");

# ---------------------
# fetch thru result set
# ---------------------
while (my $row = $sth1->fetchrow_hashref())
{

    # -------------------------------------------
    # delete row if column 'code' begins with 'C'
    # -------------------------------------------
   if ($row->{code} =~ /^C/)
   {
      $sth2->bind_param(1, $row->{code});
      $sth2->execute();
      print sprintf("DELETED: %-2s %-15s\n", $row->{code}, $row->{sname});
      next;
   }

   # --------
   # show row
   # --------
   print sprintf("%-2s %-15s\n", $row->{code}, $row->{sname});

}

# ---------------------------------------
# commit transaction and close connection
# ---------------------------------------
$dbh->do("commit");
$dbh->disconnect();

exit 0;

More Information on Perl and DBD::Informix

Resource	Location/URL
Perl Home	http://www.perl.org
Learning Perl	http://learn.perl.org
Download DBD::Informix	DBD::Informix
J. Leffler: IDS and Open Source	ids_opensource_jleffler.ppt
D. Priest: Using Perl & DBI	perl_dbi_dpriest.pdf

PHP is the language of the Web and contains an awesome function library in this area. It is the foundation for many commercial and non-commerical websites today. PHP offers a Perl like syntax, is easy to learn and allows newbies to be quickly productive. In contrast to Perl the PHP programming instructions are directly embedded in the HTML page which seems to be more intuitive to most developers. However beyond the Web, languages like Perl and Python are more dominant than PHP.

PHP 5 offers a database abstraction layer called PDO (PHP Data Objects) which is included in PHP 5.1. PDO_INFORMIX is the Informix specific implementation of this abstraction layer developed by Krishna Raman and Kellen Bombardier.

Installation steps for DB-API PDO_INFORMIX with PHP 5.1

Download PDO_INFORMIX
Create PHP with PDO as shared extension

configure -with-zlib -enable-pdo=shared

Install Informix PDO Modul
- pear install PDO_INFORMIX
Add entries to php.ini:
- extension=pdo.so
- extension=pdo_informix.so

More detailled instructions about installing and configuring PDO can be found here.

Example Program

<?php

# ------------------------------------
# open connection to database 'stores'
# ------------------------------------
$dbh = new PDO("informix:host=starship2; service=1753; database=stores; server=starship2; protocol=onsoctcp");

# ----------------
# open transaction
# ----------------
$dbh->beginTransaction();

# --------------------------------------
# prepare and execute 'select' statement
# --------------------------------------
$sth1 = $dbh->prepare("select code, sname from state");
$sth1->execute();

# --------------------------
# prepare 'delete' statement
# --------------------------
$sth2 = $dbh->prepare("delete from state where code = ?");

# ---------------------
# fetch thru result set
# ---------------------
while( $row = $sth1->fetch() )
{
    # -------------------------------------------
    # delete row if column 'code' begins with 'C'
    # -------------------------------------------
   if (strncmp($row['CODE'], "C", 1) == 0)
   {
      $sth2->BindParam(1, $row['CODE']);
      $sth2->execute();
      printf("DELETED: %-2s %-15s\n", $row['CODE'], $row['SNAME']);
      continue;
   }

    # --------
    # show row
    # --------
    printf("%-2s %-15s\n", $row['CODE'], $row['SNAME']);

}

# ---------------------------------------
# commit transaction and close connection
# ---------------------------------------
$dbh->commit();
$dbh = null;

?>

More Information on PHP and PDO_INFORMIX

Resource	Location/URL
PHP Home	http://www.php.net
Learning PHP	http://www.w3schools.com/php/default.asp
Download PDO_INFORMIX	PDO_INFORMIX
J-G. Perrin: PHP Development with IDS	php_jpg.ppt
IBM Redbook about PHP Development with IDS	http://www.redbooks.ibm.com/abstracts/sg247218.html
How to install, configure Apache,PHP,IDS on Linux	IBM developerWorks article
Google Maps API and PHP/IDS on Linux	IBM developerWorks article

Python is getting more and more popular. It has a clean, object-oriented design. Scripts written in Python have a clean structure and easy to read and maintain. The basic version of Python already contains a whole bunch of useful modules. This is called the Python batteries included philosophy, an interesting analogy to IDS Enterprise Edition which is also delivered with batteries included (Fragmentation, HDR, ER, HPL...).

There is also an interesting second implementation of Python called Jython. Jython is a pure Java implementation of the Python language and allows the developer to use Java class libraries (for example JDBC) directly in their Jython code. Check it out.

Python has quite a wide range of use. It is perfectly suited for developing ambitious software projects. However in the Web environment Perl and particulary PHP are more dominant.

The standard for accessing databases from Python is the DB-API. Carsten Haese has developed the Informix specific implemenation of this abstraction layer called the InformixDB driver.

Installation steps for DB-API InformixDB

Download DB-API InformixDB
gzcat <python_ifx_archiv> | tar xvf -
cd <python_ifx_dir>
python setup.py build_ext
python setup.py install

Example Program

#!/usr/bin/python

import sys
import informixdb  # import the InformixDB module

# ------------------------------------
# open connection to database 'stores'
# ------------------------------------
conn = informixdb.connect("stores")

# ----------------------------------
# allocate cursor and execute select
# ----------------------------------
cursor1 = conn.cursor(rowformat = informixdb.ROW_AS_DICT)
cursor1.execute('select code, sname from state')

# --------------------------
# prepare 'delete' statement
# --------------------------
cursor2 = conn.cursor()

# ---------------------
# fetch thru result set
# ---------------------
for row in cursor1:

    # -------------------------------------------
    # delete row if column 'code' begins with 'C'
    # -------------------------------------------
    if row['code'][0] == 'C':
        cursor2.execute('delete from state where code = ?', (row['code'],))
        print "DELETED: %-2s %-15s" % (row['code'], row['sname'])
        continue

   # --------
   # show row
   # --------
   print "%-2s %-15s" % (row['code'], row['sname'])


# ---------------------------------------
# commit transaction and close connection
# ---------------------------------------
conn.commit()
conn.close()

sys.exit(0);

More Information on Python and InformixDB

Resource	Location/URL
Python Home	http://www.python.org
Learning Python	http://docs.python.org/tut/tut.html
Download DB-API InformixDB	DB-API InformixDB
C. Haese: The Python InformixDB API	python_dbi_khaese.pdf

Ruby seems to be an interesting alternative to the well established script languages like Perl, PHP and Python. With the Ruby on Rails web framework, Ruby is getting more and more important in the professional web development space.

Ruby does also provide a database independent API called DBI. The actual Ruby/Informix driver written by Gerardo Santana Gomez Garrido does currently not use the DBI. Ruby/Informix is a Ruby extension written in Esql/C. Even without the DBI/DBD wrapper, it can be perfectly used to access Informix databases from the Ruby programming language. An Informix adapter for Ruby on Rails is also available (check the link section below).

Unfortunately I didn't have the time to test Ruby myself, but Gerado was so kind to translate my example program to Ruby/Informix.

Installation steps for DB-API Ruby-Informix

Here are two documents that might help:

Example Program

#!/usr/local/bin/ruby -w

require 'informix'

# ------------------------------------
# open connection to database 'stores'
# ------------------------------------
db = Informix.connect('stores')

# ----------------
# open transaction
# ----------------
db.transaction {

# --------------------------------------
# prepare cursor for 'select' statement
# --------------------------------------
  cursor = db.cursor("select code, sname from state")

# --------------------------
# prepare 'delete' statement
# --------------------------
  stmt_delete = db.prepare("delete from state where code = ?")

# ---------------------
# open cursor and fetch thru result set
# ---------------------
  cursor.open.each_hash {|row|
    # -------------------------------------------
    # delete row if column 'code' begins with 'C'
    # -------------------------------------------
    if row['code'][0].chr == 'C'
      stmt_delete.execute(row['code'])
      printf("DELETED: %-2s %-15s\n", row['code'], row['sname'])
      next
    end

    # --------
    # show row
    # --------
    printf("%-2s %-15s\n", row['code'], row['sname'])
  }.close

# ---------------------------------------
# commit transaction
# ---------------------------------------
}

# ---------------------------------------
# close connection
# ---------------------------------------
db.close

More Information on Ruby and InformixDB

Resource	Location/URL
Ruby Home	http://www.ruby-lang.org/en
Learning Ruby	http://sitekreator.com/satishtalim/toc.html
Download Ruby/Informix API	DB-API Ruby-Informix
Download Informix/Rails Adapter	Informix Adapter for Ruby Rails
Informix on Rails	Guy Bowerman's Summary