Lessons

Short, practical IBM i programming lessons.

Focused examples for RPG, SQLRPGLE, Db2 for i, APIs, DevOps, security, monitoring, and modern IBM i development.

Lesson 1RPG · 4 min read

RPG ASSERT-T and ASSERT-F: Defensive Programming on IBM i

Learn how to use RPG ASSERT-T and ASSERT-F to document and check assumptions in your code with short, practical examples.

IBM iRPGASSERT-TASSERT-FDefensive Programming
Lesson 2RPG · 3 min read

RPG %LOOKUPNE: Find the First Value That Does Not Match

Learn how to use RPG %LOOKUPNE to find the first array element that is not equal to a search value, with short practical examples.

IBM iRPG%LOOKUPNEArraysJuly 2026 RPG Enhancements
Lesson 3RPG · 4 min read

RPG LIKE(*EXT): Define a Variable Like an External File Field

Learn how RPG LIKE(*EXT) can define a variable from one field in an external file without declaring the whole file or external data structure.

IBM iRPGLIKE(*EXT)External FilesJuly 2026 RPG Enhancements
Lesson 4RPG · 4 min read

RPG ON-EXCP with Generic Message IDs

Learn how RPG ON-EXCP can monitor for generic message IDs, with short practical examples for MONITOR groups.

IBM iRPGON-EXCPMONITORGeneric Message IDs
Lesson 5RPG · 4 min read

RPG PSDS Job Type and Subtype

Learn how RPG can use the PSDS job type and subtype fields to understand how a program is running, with short practical examples.

IBM iRPGPSDSJob TypeJob Subtype