Book Image

Pentaho 3.2 Data Integration: Beginner's Guide

Book Image

Pentaho 3.2 Data Integration: Beginner's Guide

Overview of this book

Pentaho Data Integration (a.k.a. Kettle) is a full-featured open source ETL (Extract, Transform, and Load) solution. Although PDI is a feature-rich tool, effectively capturing, manipulating, cleansing, transferring, and loading data can get complicated.This book is full of practical examples that will help you to take advantage of Pentaho Data Integration's graphical, drag-and-drop design environment. You will quickly get started with Pentaho Data Integration by following the step-by-step guidance in this book. The useful tips in this book will encourage you to exploit powerful features of Pentaho Data Integration and perform ETL operations with ease.Starting with the installation of the PDI software, this book will teach you all the key PDI concepts. Each chapter introduces new features, allowing you to gradually get involved with the tool. First, you will learn to work with plain files, and to do all kinds of data manipulation. Then, the book gives you a primer on databases and teaches you how to work with databases inside PDI. Not only that, you'll be given an introduction to data warehouse concepts and you will learn to load data in a data warehouse. After that, you will learn to implement simple and complex processes.Once you've learned all the basics, you will build a simple datamart that will serve to reinforce all the concepts learned through the book.
Table of Contents (27 chapters)
Pentaho 3.2 Data Integration Beginner's Guide
Credits
Foreword
The Kettle Project
About the Author
About the Reviewers
Preface
Index

Chapter 5. Transforming Your Data with JavaScript Code and the JavaScript Step

Whichever transformation you need to do on your data, you have a big chance of finding that PDI steps are able to do the job. Despite that, it may happen that there are not proper steps that serve your requirements, or that an apparently minor transformation consumes a lot of steps linked in a very confusing arrangement difficult to test or understand. Putting colorful icons here and there is funny and practical, but there are some situations like the ones described above where you inevitably will have to code. This chapter explains how to do it with JavaScript and the special JavaScript step.

In this chapter you will learn how to:

  • Insert and test JavaScript code in your transformations

  • Distinguish situations where coding is the best option, from those where there are better alternatives