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Developing EGL based CICS DB2 Application

By sridevi S posted Mon November 01, 2021 03:12 AM


This blog walks you through end-to-end steps on, how to create an application with CICS and DB2 using EGL in the Business Developer. 

Subsystem and tools for developing the application:
Tool Used: Business Developer

Business Developer is an eclipse-based tool that generates COBOL/Java code from the developed EGL applications.

  • The Business developer is a business tool to write complex applications with minimal effort. 
  • It focuses on building business functionality rather than software technologies.
  • It can create, generate, deploy, and consume services.
  • EGL programs are written, tested, and generated to COBOL or JAVA code, later it can be deployed to the target runtime environment.

Subsystem used: CICS & DB2

  • CICS is a transaction processing system that runs under z operating system.
  • CICS allows users to develop and execute online applications in an MVS environment.
  • It communicates with the back-end system to get the desired information.
  • DB2 is a relational database management system.
  • It is a separate subsystem in mainframe where the backend data for applications is stored.

Phases of EGL to COBOL code Generation.

  • Creation phase
  • Logic phase
  • Generation phase
  • Execution phase

Creation Phase:

Creation of general project with target runtime as COBOL

File -> New -> EGL project- > Select General project and give a project name -> Click Next -> Select target runtime as COBOL-> Select the Create a build descriptor option -> Click Next -> Click Finish.

Creation of Form:

Right Click EGLSource -> New -> Other -> Select Form Group in the Select a wizard window and give Package and EGL source file name -> Click Finish.


Creation of Text UI program:

Right Click the package name -> New -> Program -> In the program window, Select Text UI program and give a program name -> Click Finish.

Logic phase:

Write logic in the Created TextUI program based on your requirement.

Example: Logic for the Add use case.   

Generation phase:

In the COBOL build descriptor: Need to specify Host details of build server along with the generation port

Execution phase in CICS region:

  • Create and install the program
  • Create and install the form(map)
  • Create and install transaction
  • Compile the program and form(map)
  • Run the Transaction (XXXX)

Use Case developed using above steps

After running the transaction xxxx, following form will be displayed in the CICS region. 

This application contains below use cases to alter DB2 using developed CICS application,

  • Fetch records
  • Add records
  • Delete records
  • Modify records

PF keys are known as function keys. PF keys allow transfer of data from terminal to CICS. PF keys are ENTER and PF1 to PF24.

Sample use case: Fetching a record.


It is important to be familiar with mainframe screen and know COBOL language and its structure to write a native COBOL code, which makes the process complicated. To overcome all the above difficulties in mainframe, Business Developer provides a user-friendly environment for COBOL generation.

Any application with various functionalities can be implemented using EGL in Business Developer as explained in this blog.