DB2 for the COBOL Programmer, Part 1

DB2 is the primary database management system (DBMS) for IBM mainframe computers that run under the z/OS operating system and its predecessors. Although you can use several different methods to work with DB2 databases, most DB2 work is done through COBOL programs. The goal of this book is to show how to develop and maintain those COBOL/DB2 programs.

Specifically, this book shows how to use Structured Query Language (SQL) within a COBOL program to retrieve and update data stored in DB2 databases. To get your students started right:

• Chapters 1 and 2 show how to retrieve data from a single DB2 table.
• Chapter 3 shows how to add rows to, delete rows from, and update rows in a single table.
• Chapter 4 shows how to retrieve data from two or more related tables at the same time by using unions and joins.

When your students complete this section, they’ll be able to write production COBOL programs.

In section 2, each of the seven chapters expands upon the basic skills so your students can process DB2 data with more expertise. For instance,

• Chapter 6 shows how to use the column functions to summarize or average the data in one column of a table.
• Chapter 8 shows how to work with variable-length columns and nulls.
• Chapter 11 shows how to maximize locking efficiency so your programs don’t tie up the system.

In this section, each chapter is written as an independent unit, so you can assign these chapters in whatever sequence you prefer.

In section 3, your students learn the skills for binding, precompiling, compiling, link editing, and testing COBOL programs:

• Chapter 12 shows how to use DB2I, which is a development tool for preparing and running DB2 programs interactively.
• Chapter 13 shows how to do these programming tasks in batch, without using DB2I.
• Chapter 14 shows how to use SPUFI, a DB2I facility, for testing SQL statements and creating test tables.
• Chapter 15 shows how to use the Query Management Facility (QMF) to add data to the test tables you create with SPUFI.

You can assign the chapters in this section any time after your students complete chapter 1.

• This is the only DB2 book written for COBOL programmers. In contrast, most other DB2 books focus on database administration or ad hoc processing to the exclusion of many of the DB2 essentials for COBOL programming.
• When your students complete section 1 of this book…just 142 pages…they’ll be developing COBOL programs that access, add, delete, or update the data in one or more DB2 tables. What’s more, they’ll understand how DB2 works.
• This book presents 12 complete COBOL programs that work with DB2 databases. These programs show how the DB2 code is coordinated with the COBOL code.

If you offer mainframe programming courses in your curriculum, this book can be used for a complete course in DB2 programming. It can also be used as an information-only supplement to a COBOL programming course to show how DB2 is integrated with COBOL in a COBOL/DB2 program on a mainframe.

Since COBOL/DB2 applications run on IBM mainframes, this book is best used in curricula that provide free access to an IBM mainframe. Then, your students can compile and test their exercises and projects on that mainframe.

If your school doesn’t have access to an IBM mainframe, you can use this book to teach DB2 programming as an information-only course. Then, you won’t need a computer lab at all. This can work in conjunction with a COBOL course when you just want your students to know what’s different about DB2 programming and where it fits in the IT job market.