Use Embedded SQL for Row and Column Retrieval

摘要

Using SQL in your RPG applications is a great way to modernize your programs and, in many cases, simplify your coding. In this article, I show how to use embedded SQL to perform row (record) and column (field) retrieval and explain when to use which SQL statement. You'll see that it's easy to do most if not all your table (file) access in SQL without the need for F-specs.rnAlthough SQL terminology uses the word "table" for "file," the word "row" for "record," and the word "column" for "field," for the remainder of this article, I use the IBM i/RPG terminology of files, records, and fields. I use SQL terminology in the code comments, though, so we can all get more used to seeing SQL terminology. To keep the code focused on the topic, I include no robust error checking after each statement. I provide the basics, though, of what you need to check for after an SQL statement runs. Because you must have more error checking in your production applications, make sure you review "Foolproof Guide to Embedded SQL Error Handling" (May 2007, article ID 20877 at SystemiNetwork.com). For more information about working with SQL, also check out "Working with Multiple Tables in SQL" (March 2008, article ID 21170).