Oracle Application Express is an easy-to-use application development environment built on the Oracle technology stack. There are two aspects of that previous sentence that you may find jarring--that Oracle, a company widely known for its database technology, has an application development environment, and that Oracle, a company thought of as delivering high-end, enterprise-ready technology, has anything that is easy to use. But, as this book will show, the introductory statement is completely accurate. Oracle Application Express, commonly known as Oracle APEX or simply APEX, does benefit from the long-established enterprise-class robustness that is the hallmark of Oracle technology. The applications you build will be able to support hundreds of users and many terabytes of data, scalability far beyond even the imagination of most other development environments. And Oracle APEX, with its declarative, wizard-driven methodology, is truly easy to use. In the course of the few hundred pages of this book, you will not only learn about how to use APEX, you will create a usable order entry system. The fast learning curve presented in these pages is a consequence of many years of development and refinement of the APEX product, which began life almost a decade ago within Oracle. By the end of this volume, you will know enough to create your own applications, as well as having the knowledge and understanding of Oracle APEX and the world of Oracle technology to explore further refinements on your own. Best of all, you can use APEX with absolutely no cost--either in a hosted environment, as suggested in Chapter 1, or with a free version of the Oracle database. Welcome to the world of Oracle Application Express! This book is aimed at a particular group of users--those who are not familiar with Oracle Application Express. The book assumes that you have a basic knowledge of application development, the type you could get from playing around with a personal database such as Access. In fact, this book was written with an Access developer in mind--an Access developer looking to step up to a more scalable and reliable environment, with reduced maintenance overhead and greater integration between application systems. This book covers the use of Oracle Application Express. Although the book is based on the 3.5 version, you can use the book with older versions as well. However, since the book will use a hosted version of Oracle Application Express, and since both the Oracle database that support the product and the product itself are available as free downloads from http://otn.oracle.com, you should be able to use the latest version easily. This book is structured to give the reader a gradual introduction to the essentials of development with Oracle Application Express. The book contains the following: Welcome to Oracle!--This contains an overview of Oracle Application Express, as well as instructions on how to set up a hosted development environment for performing the exercises used in the book. Jumpstart Oracle Application Express--You will leap into creating applications with Oracle Application Express and finish a simple application by the end of this. Extending Your Oracle APEX Application--This will introduce you to the options in Oracle APEX that let you ensure that your users will enter correct data while using your application. Validation, Calculation, Navigation, and Lists--This continues the exploration of the aspects of APEX that help you to ensure that data used in your applicat...