Book Image

Pentaho Data Integration Beginner's Guide - Second Edition - Second Edition

By : María Carina Roldán
Book Image

Pentaho Data Integration Beginner's Guide - Second Edition - Second Edition

By: María Carina Roldán

Overview of this book

Capturing, manipulating, cleansing, transferring, and loading data effectively are the prime requirements in every IT organization. Achieving these tasks require people devoted to developing extensive software programs, or investing in ETL or data integration tools that can simplify this work. Pentaho Data Integration is a full-featured open source ETL solution that allows you to meet these requirements. Pentaho Data Integration has an intuitive, graphical, drag-and-drop design environment and its ETL capabilities are powerful. However, getting started with Pentaho Data Integration can be difficult or confusing. "Pentaho Data Integration Beginner's Guide - Second Edition" provides the guidance needed to overcome that difficulty, covering all the possible key features of Pentaho Data Integration. "Pentaho Data Integration Beginner's Guide - Second Edition" starts with the installation of Pentaho Data Integration software and then moves on to cover all the key Pentaho Data Integration concepts. Each chapter introduces new features, allowing you to gradually get involved with the tool. First, you will learn to do all kinds of data manipulation and work with plain files. Then, the book gives you a primer on databases and teaches you how to work with databases inside Pentaho Data Integration. Moreover, you will be introduced to data warehouse concepts and you will learn how to load data in a data warehouse. After that, you will learn to implement simple and complex processes. Finally, you will have the opportunity of applying and reinforcing all the learned concepts through the implementation of a simple datamart. With "Pentaho Data Integration Beginner's Guide - Second Edition", you will learn everything you need to know in order to meet your data manipulation requirements.
Table of Contents (26 chapters)
Pentaho Data Integration Beginner's Guide
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Best Practices
Index

Time for action – reading all your files at a time using a single text file input step and regular expressions


You can do the same thing that you did previously by using a different notation. Follow these instructions:

  1. Open the transformation that reads several files and double-click on the Input step.

  2. Delete the lines with the names of the files.

  3. In the first row of the grid, under the File/Directory column, type the full path of the input folder, for example C:\pdi_files\input.

  4. Under the Wildcard (RegExp) column type (usa|europe)_[0-9]{6}\.txt.

  5. Click on the Show filename(s)... button. You will see the list of files that match the expression:

  6. Close the tiny window and click on Preview rows to confirm that the rows shown belong to the files that match the expression you typed.

What just happened?

In this case, all the filenames follow a pattern: usa_201209.txt, usa_201210.txt, and so on. So, in order to specify the names of the files you used a regular expression. In the column File/Directory...