IBM i fans only - tips and tricks to start RPG free format programming with simple examples

#IBMiSample – Improve Subfile Performance by Loading One Page at a Time  The traditional subfile can display up to 9,999 rows and works perfectly in many scenarios. However, when dealing with large datasets or heavy filtering , loading every matching record before showing the first page can drastically slow down the user experience. Based on comments I received from IBM i developers, here are two practical cases that clearly explain why loading only one page at a time is often a better solution. Scenario 1 — Small File Subfile size: 20 rows Total records: 5,000 Filtered records: 280 (for example: FLAG = 'X' and creation date in a selected range) With a standard subfile , the program displays the first page only after scanning all 5,000 records . With a single-page load , the program stops as soon as it finds the first 20 matching records and immediately displays the first screen. This is significantly faster and improves usabilit...

How to Use GET DIAGNOSTICS in SQLRPGLE to Retrieve Row Count on IBM i In this post, I’ll walk you through a simple and effective way to retrieve the number of rows affected by SQL statements in your SQLRPGLE programs using the GET DIAGNOSTICS statement. Whether you're inserting, updating, or deleting rows, GET DIAGNOSTICS allows you to programmatically capture how many records were impacted. What You'll Learn How to use GET DIAGNOSTICS after an SQL operation How to check the number of rows inserted, updated, or deleted A practical example using two test tables Prerequisites Before running the example, create two tables using these SQL statements: CREATE TABLE TESTFILE ( TFTYPE CHAR(2) NOT NULL WITH DEFAULT, TFNUMB NUMERIC(7, 0) NOT NULL WITH DEFAULT ); CREATE TABLE TESTFILE2 ( TFTYPE CHAR(2) NOT NULL WITH DEFAULT, TFNUMB NUMERIC(7, 0) NOT NULL WITH DEFAULT ); Then populate TESTFILE with the following sample data: INSERT INTO T...

Using a Parameterized Cursor in SQLRPGLE – A Simple and Clean Example When working with embedded SQL on IBM i, using a cursor with parameters is a great way to selectively retrieve data from a file based on runtime input. In this post, I’ll walk you through a simple SQLRPGLE program that demonstrates this concept. This free-format RPG example shows how to: Accept an input parameter Open a cursor based on that parameter Fetch records from the CLANA00F file Display basic customer information Properly handle SQL errors What Is CLANA00F? The file CLANA00F contains customer master data. Here's a simplified layout of its most relevant fields: Field Type Description CLCCL0 S(7) Customer numeric ID CLNOM0 A(50) Customer name CLCIB0 A(3) International code Our goal is to retrieve only those customers whose CLCIB0 matches a parameter passed when the program is called. Program Highlights ctl-opt dftactgrp(*no) actgrp(*caller); dcl-s CLCCL0...

Simple Example of Using Dynamic SQL in RPG Dynamic SQL is a powerful technique on IBM i that allows you to build SQL statements at runtime instead of hardcoding them. This flexibility is essential when your SQL needs to adapt based on user input, configuration, or variable conditions. In this post, I’ll walk you through a simple RPG example that uses a parameterized dynamic SQL statement to retrieve data from a file. The Program **FREE // ************************************************************* // * Author.......: ALDO SUCCI                                 * // * Description..: Simple example of using dynamic SQL in RPG * // *************************************************************   // Declare variable to hold the customer type (3 characters) dcl-s wCLCIB0 CHAR(3);   // Declare variable to hold the customer name retrieved from the database dcl-s wCLNOM...

SQL Indicator Variables in Embedded SQL for RPG on IBM i When working with DB2 on IBM i, handling NULL values properly is essential, especially when you retrieve data using embedded SQL in RPG. In this post, I’ll show you a simple and practical way to check if a column is NULL using what’s called an SQL Indicator Variable . The Scenario Let’s say you have a customer file called CLANA00F with the following fields: Field Type Length Description CLANN0 CHAR(1) 1 Customer status CLCCL0 DEC(7,0) 7 Customer ID CLCIB0 CHAR(3) 3 Customer type CLNOM0 CHAR(50) 50 Customer name CLSTS0 CHAR(1) 1 Customer status Now, imagine that CLSTS0 is nullable (i.e., it can contain NULL ), and you want to find out whether it has a value or not. The RPG Example **free ctl-opt dftactgrp ( *no ) actgrp ( *caller ); // **************************************************************** // * Autore.......: ALDO SUCCI ...