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IBM i Fundamentals · Lesson 1Product preview

What is IBM i?

A beginner-friendly introduction to the platform that runs on IBM Power Systems.

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IBM i Fundamentals

A complete, 288-lesson path from what the platform is to a basic development workflow -- covering libraries and objects, the 5250 interface, RPGLE, CLLE, Db2 for i, and job logs. Lesson 1 is free to preview without an account.

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  1. 1What is IBM i?
  2. 2Why IBM i Still Matters
  3. 3IBM i Platform Overview
  4. 4Libraries and Objects
  5. 55250 Screen Basics
  6. 6Physical Files and Logical Files
  7. 7Introduction to RPGLE
  8. 8Introduction to CLLE
  9. 9Introduction to Db2 for i
  10. 10Job Logs and Spool Files Basics
  11. 11Basic IBM i Development Workflow
  12. 12Where to Go Next
  13. 13AS/400, iSeries, and IBM i Naming Explained
  14. 14IBM i Access Client Solutions Overview
  15. 15Signing On, User Profiles, and Current Library
  16. 16Understanding IBM i Command Structure
  17. 17Using F4 Prompt and Command Help
  18. 18Common IBM i Object Types
  19. 19Library List Explained in Depth
  20. 20Source Physical Files and Source Members
  21. 21IFS Basics for IBM i Beginners
  22. 22Native Objects vs Stream Files
  23. 23Object Naming and Qualified Names in Practice
  24. 24Working with WRKOBJ, DSPOBJD, and WRKLIB
  25. 25DDS and SQL: Two Ways to Define Db2 for i Data
  26. 26Physical Files Explained in Depth
  27. 27DDS Field Definitions
  28. 28Keyed Physical Files
  29. 29Logical Files Explained in Depth
  30. 30Access Paths and Why They Matter
  31. 31SQL Tables vs DDS Physical Files
  32. 32Basic SELECT on IBM i
  33. 33RPGLE Program Structure
  34. 34RPGLE Source Layout and Free Format Basics
  35. 35Variables and Data Types in RPGLE
  36. 36Constants and Literals in RPGLE
  37. 37Expressions and Assignment in RPGLE
  38. 38IF / ELSE in RPGLE
  39. 39SELECT / WHEN / OTHER in RPGLE
  40. 40DO Loops and Basic Iteration in RPGLE
  41. 41Built-in Functions in RPGLE
  42. 42Data Structures in RPGLE
  43. 43Arrays in RPGLE
  44. 44Indicators in Modern RPGLE
  45. 45Procedures and Subprocedures in RPGLE
  46. 46Parameters and Prototypes in RPGLE
  47. 47Basic Error Handling in RPGLE
  48. 48Debugging RPGLE Programs
  49. 49When to Use CLLE vs RPGLE
  50. 50CLLE Program Structure
  51. 51CL Commands and Parameters
  52. 52Variables in CLLE
  53. 53IF, DO, and Basic Control Flow in CLLE
  54. 54Calling RPGLE Programs from CLLE
  55. 55MONMSG and Basic Error Handling in CLLE
  56. 56SBMJOB and Batch Job Basics
  57. 57Passing Parameters to CLLE Programs
  58. 58Calling RPGLE Programs with Parameters from CLLE
  59. 59Working with IBM i Job Attributes in CLLE
  60. 60Checking Objects with CHKOBJ
  61. 61Sending and Receiving Messages in CLLE
  62. 62Data Areas in CLLE
  63. 63Using CLLE for Batch Job Orchestration
  64. 64Common CLLE Mistakes and Best Practices
  65. 65What is a Display File in IBM i?
  66. 665250 Screen Design Basics
  67. 67Display File Record Formats
  68. 68Input Fields, Output Fields, and Both Fields
  69. 69Function Keys and Response Indicators
  70. 70Basic Display File DDS Keywords
  71. 71RPGLE Program Calling a Display File
  72. 72Simple Inquiry Screen Flow
  73. 73Display File Indicators Explained
  74. 74Function Keys in More Depth
  75. 75Screen Field Validation Basics
  76. 76Displaying Error Messages on 5250 Screens
  77. 77Window Records and Simple Popup Screens
  78. 78READ, WRITE, EXFMT, and Screen Flow
  79. 79Basic Inquiry Screen Pattern
  80. 80Common Display File Mistakes and Best Practices
  81. 81What is a Subfile in IBM i?
  82. 82Subfile Record Format vs Subfile Control Record Format
  83. 83SFLDSP, SFLDSPCTL, and SFLCLR Explained
  84. 84Load-All Subfile Concept
  85. 85Page-at-a-Time Subfile Concept
  86. 86Simple Inquiry Subfile Pattern
  87. 87Function Keys in Subfile Programs
  88. 88Common Subfile Mistakes and Best Practices
  89. 89Understanding RRN in Subfile Programs
  90. 90Clearing and Reloading a Subfile
  91. 91Using SFLEND to Show End of List
  92. 92Option Fields in Subfile Screens
  93. 93Selecting a Row in a Subfile
  94. 94Basic Update/Delete Subfile Pattern
  95. 95Introduction to SFLNXTCHG
  96. 96Debugging Subfile Programs
  97. 97RPGLE File Declarations with dcl-f
  98. 98Reading Physical Files in RPGLE with READ
  99. 99Understanding %EOF in RPGLE File Processing
  100. 100CHAIN for Keyed Access
  101. 101Understanding %FOUND after CHAIN
  102. 102Writing Records with WRITE
  103. 103Updating Records with UPDATE
  104. 104Deleting Records with DELETE
  105. 105SETLL in RPGLE
  106. 106READE for Reading Matching Keys
  107. 107READP and Reading Backward
  108. 108Processing Duplicate Keys in RPGLE
  109. 109Basic File Locking Concept in RPGLE
  110. 110Handling File I/O Errors at a Beginner Level
  111. 111Debugging RPGLE File I/O Programs
  112. 112Common RPGLE File I/O Mistakes and Best Practices
  113. 113What is SQLRPGLE?
  114. 114Native RPGLE File I/O vs Embedded SQL
  115. 115Basic EXEC SQL Syntax in RPGLE
  116. 116Host Variables in SQLRPGLE
  117. 117SELECT INTO for Reading One Row
  118. 118Using SQL Cursor to Read Multiple Rows
  119. 119INSERT with Embedded SQL
  120. 120UPDATE and DELETE with Embedded SQL
  121. 121SQLCODE and SQLSTATE Basics in SQLRPGLE
  122. 122Handling No Row Found in SQLRPGLE
  123. 123FETCH Loop for Reading Multiple Rows
  124. 124Basic WHERE Conditions in Embedded SQL
  125. 125ORDER BY and Result Ordering
  126. 126Simple JOIN in SQLRPGLE
  127. 127NULL Handling Basics in SQLRPGLE
  128. 128Common SQLRPGLE Mistakes and Best Practices
  129. 129What is a Printer File in IBM i?
  130. 130Printer File DDS Basics
  131. 131Report Record Formats
  132. 132RPGLE Program Writing to a Printer File
  133. 133Report Headings and Detail Lines
  134. 134Page Overflow Basics
  135. 135Spool Files and Output Queues
  136. 136Common Printer File Mistakes and Best Practices
  137. 137Report Totals and Summary Lines
  138. 138Multi-Record Format Reports
  139. 139Controlling Page Breaks
  140. 140Working with Spool Files using WRKSPLF
  141. 141Working with Output Queues using WRKOUTQ
  142. 142Printer File Overrides Basics
  143. 143Debugging Report Output Problems
  144. 144Printer File vs Display File vs Database File
  145. 145Why Debugging Matters on IBM i
  146. 146STRDBG Basics for RPGLE
  147. 147Setting and Using Breakpoints
  148. 148Watching Variables During Debug
  149. 149Understanding Job Logs
  150. 150Reading IBM i Message IDs
  151. 151Compile Errors vs Runtime Errors
  152. 152Common IBM i Debugging Mistakes
  153. 153DSPJOB and Job Information Basics
  154. 154WRKACTJOB Basics for Developers
  155. 155Finding Program Failures from Error Messages
  156. 156Understanding Call Stack Basics
  157. 157Debugging Batch Jobs at a Beginner Level
  158. 158Using Job Logs for SQLRPGLE and File I/O Issues
  159. 159Basic Troubleshooting Flow for IBM i Developers
  160. 160Debugging Checklist for Beginners
  161. 161IBM i Jobs Explained
  162. 162Interactive Jobs vs Batch Jobs
  163. 163Job Queues and Output Queues
  164. 164Subsystems Basics
  165. 165Library List in Real Job Execution
  166. 166Object Locks Basics
  167. 167Authorities and Object Access Basics
  168. 168Common IBM i Operations Commands for Developers
  169. 169Submitted Jobs and WRKSBMJOB
  170. 170Job Logs in Batch Jobs
  171. 171Job Status Values Explained
  172. 172Basic Job Scheduling Concepts
  173. 173Handling Object Locks as a Developer
  174. 174Authority Failures and How to Investigate Them
  175. 175Library List Problems in Real Applications
  176. 176Common IBM i Operations Mistakes and Best Practices
  177. 177Mini Project: Customer Inquiry Program
  178. 178Mini Project: Item Master Lookup Program
  179. 179Mini Project: Simple Order List Subfile
  180. 180Mini Project: Batch Report Program
  181. 181Mini Project: CLLE Wrapper to Run a Report
  182. 182Mini Project: SQLRPGLE Customer Lookup
  183. 183Mini Project: Debugging a Broken File I/O Program
  184. 184Mini Project: End-to-End Mini DMS-Style Flow
  185. 185Mini Project: Customer Maintenance Add/Change/Delete
  186. 186Mini Project: Order Entry Skeleton
  187. 187Mini Project: Report with CLLE Submit Job Flow
  188. 188Mini Project: Subfile Row Selection with Detail Screen
  189. 189Mini Project: SQLRPGLE Search Screen
  190. 190Mini Project: Printer File Report with Totals
  191. 191Mini Project: Troubleshooting Locked Record Scenario
  192. 192Mini Project: Batch Job Failure Investigation
  193. 193IBM i Developer Interview Roadmap
  194. 194RPGLE Basic Interview Questions
  195. 195RPGLE File I/O Interview Scenarios
  196. 196CLLE Interview Scenarios
  197. 197SQLRPGLE Interview Scenarios
  198. 198Display File and Subfile Interview Questions
  199. 199Debugging Scenario-Based Questions
  200. 200Real Support Ticket Analysis for Beginners
  201. 201Explaining Your IBM i Project Experience
  202. 202RPGLE Scenario-Based Interview Practice
  203. 203SQLRPGLE vs Native I/O Interview Discussion
  204. 204Debugging Live Issue Interview Practice
  205. 205IBM i Support Ticket Walkthrough
  206. 206Resume Points for IBM i Developers
  207. 207Common IBM i Interview Mistakes
  208. 208Mock IBM i Developer Interview
  209. 209OPM vs ILE on IBM i
  210. 210What are Modules, Programs, and Service Programs?
  211. 211Creating RPGLE Modules with CRTRPGMOD
  212. 212Binding Modules into Programs with CRTPGM
  213. 213Prototypes and Procedure Interfaces in ILE
  214. 214Internal Procedures vs Exported Procedures
  215. 215Introduction to Service Programs
  216. 216Activation Groups Basics
  217. 217Binding Directories Basics
  218. 218Creating Service Programs with CRTSRVPGM
  219. 219Binder Source Introduction
  220. 220Service Program Signatures at a Beginner Level
  221. 221Updating Service Programs Safely
  222. 222Activation Group Problems and Common Confusions
  223. 223Debugging ILE Programs
  224. 224Common ILE Mistakes and Best Practices
  225. 225Modern IBM i Development Overview
  226. 226Why APIs Matter on IBM i
  227. 227REST API Concepts for IBM i Developers
  228. 228JSON Basics for RPGLE Developers
  229. 229IFS and API Payload Files
  230. 230Calling External APIs from IBM i
  231. 231Exposing IBM i Logic as an API
  232. 232Common IBM i Integration Mistakes
  233. 233HTTP Methods and Status Codes for IBM i Developers
  234. 234API Request and Response Design Basics
  235. 235JSON Parsing Concepts in RPGLE
  236. 236API Error Handling Basics
  237. 237Logging Integration Requests and Responses
  238. 238Securing IBM i APIs at a Beginner Level
  239. 239Batch vs Real-Time Integration
  240. 240Debugging API Integration Issues
  241. 241DDL on IBM i: CREATE TABLE, ALTER TABLE, and DROP TABLE
  242. 242SQL Indexes and Views on Db2 for i
  243. 243Constraints on IBM i: Primary Key, Foreign Key, Unique, and Check
  244. 244ACS Run SQL Scripts for IBM i Developers
  245. 245SQL Stored Procedures on IBM i
  246. 246External Stored Procedures with RPGLE
  247. 247SQL Triggers on IBM i
  248. 248User-Defined Functions on IBM i
  249. 249SQLCA, SQLCODE, and SQLSTATE in Depth
  250. 250Static SQL vs Dynamic SQL on IBM i
  251. 251SQL Precompilation with CRTSQLRPGI
  252. 252Query Optimization Basics on Db2 for i
  253. 253SQE vs CQE at a Beginner-Friendly Level
  254. 254Encoded Vector Indexes Introduction
  255. 255DRDA and Distributed Database Concepts
  256. 256Common Advanced SQL Mistakes on IBM i
  257. 257User Profiles and Group Profiles on IBM i
  258. 258Object Authority in Depth
  259. 259Public Authority and Private Authority in Depth
  260. 260Authorization Lists on IBM i
  261. 261Special Authorities Explained
  262. 262Adopted Authority Basics
  263. 263Investigating Authority Failures in Depth
  264. 264IBM i Security Best Practices for Developers
  265. 265QSECURITY System Value Explained
  266. 266Auditing Basics and QAUDJRN Overview
  267. 267Exit Points and Exit Programs Overview
  268. 268IFS Security Basics
  269. 269Digital Certificates and TLS Concepts on IBM i
  270. 270Row and Column Access Control and Field Procedures Overview
  271. 271Authority Collection Overview
  272. 272Common IBM i Security Mistakes and Best Practices
  273. 273What is Journaling on IBM i?
  274. 274Journal Receivers Explained
  275. 275Starting Journaling with STRJRNPF
  276. 276Viewing Journal Entries Basics
  277. 277Commitment Control Overview
  278. 278STRCMTCTL, COMMIT, and ROLLBACK Basics
  279. 279Journaling for Recovery and Auditing
  280. 280Common Journaling and Commitment Control Mistakes
  281. 281Why Backup and Restore Matter on IBM i
  282. 282SAVOBJ and RSTOBJ Basics
  283. 283SAVLIB and RSTLIB Basics
  284. 284Save Files Explained
  285. 285GO SAVE Options 21, 22, and 23 Overview
  286. 286Restoring Objects Safely in Development and Test
  287. 287Backup vs Journaling vs High Availability
  288. 288Common Save/Restore Mistakes

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Explain the difference between a physical file and a logical file.
A physical file stores the actual data. A logical file doesn't store data itself -- it defines a view, like a subset of columns or an alternate access path, over one or more physical files.
What is a job log in IBM i?Show a simple RPGLE example.
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