Learn RPG4 with Real Code Examples
Updated Nov 27, 2025
Practical Examples
Reading/writing Db2 records
Processing daily batch files
Creating REST/JSON APIs via RPG + IWS
ERP data transformation programs
Interactive display file applications
Troubleshooting
Check library list ordering
Verify file locks
Debug using STRDBG
Inspect activation groups
Confirm SQL commitment control level
Testing Guide
Unit test procedures
Use STRDBG for interactive debugging
Test file-level locks and commit levels
Test with multiple activation groups
Validate SQL performance with Visual Explain
Deployment Options
Bound programs (CRTBNDRPG)
Modules + service programs
CL wrappers
API endpoints via IWS
Batch jobs in job scheduler
Tools Ecosystem
RDi (Rational Developer for i)
VS Code + Code for IBM i
ACS (Access Client Solutions)
IBM i Navigator
Db2 tooling (RUNSQLSTM, ACS SQL editor)
Integrations
Db2 for i SQL and native I/O
REST APIs (IWS / YAJL JSON)
MQ messaging
FTP/SFTP for batch transfers
CL programs and job schedulers
Productivity Tips
Use VS Code + Code for IBM i
Adopt SQL-centric design
Automate compilation with scripts
Use binding directories
Modularize early
Challenges
Legacy code maintenance
Handling fixed-format RPG
Understanding library lists
ILE activation group complexities
Interfacing with modern APIs