Book Image

IBM DB2 9.7 Advanced Application Developer Cookbook

Book Image

IBM DB2 9.7 Advanced Application Developer Cookbook

Overview of this book

With lots of new features, DB2 9.7 delivers one the best relational database systems in the market. DB2 pureXML optimizes Web 2.0 and SOA applications. DB2 LUW database software offers industry leading performance, scale, and reliability on your choice of platform on various Linux distributions, leading Unix Systems like AIX, HP-UX and Solaris and MS Windows platforms. This DB2 9.7 Advanced Application Developer Cookbook will provide an in-depth quick reference during any application's design and development. This practical cookbook focuses on advanced application development areas that include performance tips and the most useful DB2 features that help in designing high quality applications. This book dives deep into tips and tricks for optimized application performance. With this book you will learn how to use various DB2 features in database applications in an interactive way.
Table of Contents (15 chapters)
IBM DB2 9.7 Advanced Application Developer Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface

Using scalar user-defined functions


User-defined functions provide us with the ability to group a set of statements or instructions which can perform a task. A simple example would be a function that returns the sum of values. Functions can be designed to return a scalar value, a row, or a table. Similar to the stored procedures, user-defined functions can also be designed in SQL or any high-level programming language and they also accept input parameters and return the result. In this recipe, we will focus on the simplest form of functions, which is a scalar function. As the name suggests, a scalar function returns a scalar value. DB2 provides many scalar in-built functions like SUM(), AVG(), MAX(), MIN(), and so on. Scalar functions are commonly used for string manipulation, mathematical operations, and so on.

Getting ready

We need the following privileges to create a stored procedure:

  • The CREATIN or IMPLICIT schema privilege, whichever is applicable

  • The SELECT privileges on each...