Chapter 6. Writing an application program

• Using integrated development environments 178

• Choosing programming languages and methods to use 181

• Preparing an application program to run 182

• Writing static SQL applications 185

• Writing dynamic SQL applications 194

• Using ODBC to execute dynamic SQL 196

• Using Java to execute static and dynamic SQL 198

• Using an application program as a stored procedure 202

• For more information 209

• Practice exam questions 212

• Answers to practice exam questions 214

This chapter introduces the basic concepts of writing an application program to access data in a DB2 database. Programmers have a wide variety of choices for designing their database applications. Those choices range from single-tier applications, in which the logic and data all reside on zSeries, to multitier applications. A complex multitier application might have a browser client with business application logic for data access that runs on a middle-tier Web application server and database logic that runs with the database server as stored procedures.

You have a wide range of options not only for the architecture of your application, but also for the tools and languages that you use for development. Because writing an application program varies for each programming language and for each style of application, this chapter does not attempt to teach you how to become an application programmer. Rather, it covers the general coding concepts that you need to know that are specific to DB2 UDB for z/OS. You can apply these concepts to the various languages. The chapter explains several different techniques that you can use to write an application program for DB2.

Details are given primarily for the portions of the application that run on z/OS. Client applications that run on other operating systems and that access DB2 UDB for z/OS data are discussed briefly.