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

Time for action – generating custom files by executing a transformation for every input row


Suppose that 60 is the threshold below which a student must retake the examination. Let's find out the list of students with a score below 60, that is, those who didn't succeed in the writing examination. Then, let's create one file per student telling him/her about this.

First of all, let's create a transformation that generates the list of students who will take the examination:

  1. Create a new transformation.

  2. Drag a Text file input, a Filter rows, and a Select values step to the canvas and link them in that order.

  3. Use the Text file input step to read the global examination file.

  4. Use the Filter rows step to keep only those students with a writing score below 60.

  5. With the Select values step, keep just the student_code and name values.

  6. After this last step, add a Copy rows to result step.

  7. Do a preview on this last step. You will see the following (the exact names and values depend on the number of files you...