Book Image

Pentaho Data Integration 4 Cookbook

Book Image

Pentaho Data Integration 4 Cookbook

Overview of this book

Pentaho Data Integration (PDI, also called Kettle), one of the data integration tools leaders, is broadly used for all kind of data manipulation such as migrating data between applications or databases, exporting data from databases to flat files, data cleansing, and much more. Do you need quick solutions to the problems you face while using Kettle? Pentaho Data Integration 4 Cookbook explains Kettle features in detail through clear and practical recipes that you can quickly apply to your solutions. The recipes cover a broad range of topics including processing files, working with databases, understanding XML structures, integrating with Pentaho BI Suite, and more. Pentaho Data Integration 4 Cookbook shows you how to take advantage of all the aspects of Kettle through a set of practical recipes organized to find quick solutions to your needs. The initial chapters explain the details about working with databases, files, and XML structures. Then you will see different ways for searching data, executing and reusing jobs and transformations, and manipulating streams. Further, you will learn all the available options for integrating Kettle with other Pentaho tools. Pentaho Data Integration 4 Cookbook has plenty of recipes with easy step-by-step instructions to accomplish specific tasks. There are examples and code that are ready for adaptation to individual needs.
Table of Contents (17 chapters)
Pentaho Data Integration 4 Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Executing part of a job several times until a condition is true


Suppose that you have a list of tasks that have to be repeated while or until a condition is true (or false). If you know about programming languages, think of this as an analogy of a while or repeat until loop. Kettle allows you to implement these kinds of iterations and this recipe explains how to do it.

For the recipe, you will use one of the transformations described in the introduction of this chapter: the transformation that generates random numbers and writes them to a file. You will execute the transformation repeatedly and keep track of the number of lines written to those files. You will continue executing the transformation as long as the total number of written lines is less than 25.

Getting ready

You will need the transformation that generates random numbers described in the introduction. If instead of downloading the transformation you created it yourself, then you will have to do a quick fix in order to make Kettle...