Book Image

QlikView 11 for Developers

Book Image

QlikView 11 for Developers

Overview of this book

Business Intelligence technologies are a must-have in every business to make informed decisions and keep up-to speed with the ever-evolving markets. QlikView's disruptive technology makes it a key player and leader in the industry; with its flexibility and powerful analytics environment, building QlikView apps can be mastered by both, business users as well as developers. This book will help you learn QlikView Development from a basic to a practitioner level using a step-by-step approach in a practical environment, and apply proven best practices on each topic. Throughout the book, we will build a QlikView app based on real data about Airline Operations that will help "HighCloud Airlines" make informed business decisions and analysis-guided strategies. HighCloud Airlines executives are evaluating if entering the US market is a good strategy and, if so, which line of business should they focus their investments on; they need QlikView to make the best decision. The application will be evolving chapter by chapter, along with your skills, going from a simple proof of concept to creating a Data Model, adding a custom style, building a Dashboard and handling and manipulating the source data via script. We will meet the "HighCloud Airlines" requirement by using many different data visualization objects and time-saving techniques. The whole application uses real data taken from the Bureau of Transportations statistics of the US and encompasses the operations of Airlines both domestic and international. With three years worth of data, you will help HighCloud Airlines discover where people travel the most, which are the Carriers with the most market share, what is the average load factor per airline, which aircraft is the most used to perform flights, which are the busiest airports, and a whole universe of new insights.
Table of Contents (23 chapters)
QlikView 11 for Developers
Credits
Foreword
About the Authors
Acknowledgements
About the Reviewers
www.PacktPub.com
Preface
Index

The Aggr function


The output of the Aggr function can be likened to the list of values a straight table would display when evaluating an expression over a certain dimension. For instance, the following straight table has the Flight Type field as the dimension and Sum([# Departures Performed]) as the expression.

Essentially, the Aggr function creates a virtual straight table, similar to the earlier one, so that we can further process the list of values that would appear in the expression column, without even creating the actual object. The result of the Aggr function can be used to:

  • Create a calculated dimension and perform a nested aggregation

  • Perform additional aggregations based on the resulting set of values

Let's see examples for both of these.

Using Aggr for nested aggregation

Since HighCloud Airlines' users are interested in discovering key players in the industry from different perspectives, they now require a visualization object that clearly identifies carrier coverage of interstate...