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 – getting variables for setting the default starting date


Let's modify the transformation so that the starting date depends on a parameter.

  1. Press Ctrl+T to open the transformation settings window.

  2. Add a parameter named START_DATE with default value 01/12/1999.

  3. Add a Get variables step between the Calculator step and the Filter rows step .

  4. Edit the Get variables step and a new field named start_date. Under Variable write ${START_DATE}. As Type select Date, and under Format select or type dd/MM/yyyy.

  5. Modify the filter step so the condition is now: date>=start_date and date<=31/12/2020.

  6. Modify the Select values step to remove the start_date field.

  7. With the Select values step selected do a preview. You will see this:

What just happened?

You added a starting date as a named parameter. Then you read that variable into a new field and used it to keep only the dates that are greater or equal to its value.

Using the Get Variables step

As you just saw, the Get Variables step allows you...