SQL is a great tool when used properly, and this article gives you a simple, practical example to get you started.

By Joe Pluta

Welcome to the wonderful world of practical SQL for RPG programmers. Over the coming months, I hope to bring you a whole host of practical techniques that you can use to become more productive using SQL in your daily programming efforts. I know it may seem odd to some to hear me giving advice on SQL, since over the years I've been very steadfast in my opinion that SQL should not replace native I/O for business logic. But really, there is no conflict here; I have always believed in the best tool for the job, and there are times when SQL is definitely the best tool.

Procedures and functions, whether written in SQL or in traditional application development languages, provide powerful tools for accessing your database.

By Kevin Forsythe

One of the most difficult tasks when you're designing an application is deciding how to code each portion of the application. We can develop applications in CL, RPGLE, SQL, and a host of other languages. The capabilities of these languages overlap one another to a certain degree, so the decision of which language to use is not always clear-cut.

Use an SQL user-defined table function (UDTF) to access messages in a message file.

By Mike Faust

If you've ever needed to retrieve information from a message file, you're probably already aware of the Retrieve Message (QMHRTVM) API, which allows you to retrieve message descriptions for messages in a specified message file. But is that enough?

Getting the most benefit out DB2 for i requires keeping the concept of "set at time" in mind and making use of all the latest features and functions.

By Mike Cain

In Dan Cruikshank's August 2008 article "Working with Data Sets," Dan illuminated the power of SQL "set at a time" processing, and he used some of the new DB2 for i 6.1 OLAP functions to do it. In this article, I'll expand on this concept and demonstrate some additional uses for OLAP functions, as well as reiterate the reasons that SQL can be so powerful for the data-centric programmer. We'll also take a look at some of the performance considerations for more-complex SQL requests.

Why are the examples for SQL always so lame? It's time to see what you can do with SQL on a real-world database.

By Joe Pluta

Seriously, how often do you change the price in an entire price file by 15 percent? I don't know of a single situation in my career where that has happened. Yet that's the same lame example we see in every "SQL for business" book. Yes, SQL is great for handling sets of data, but more often than not, in the real world you have to do some analysis, some aggregation, some extraction, and then finally some manipulation. The good news is that SQL gives you lots of tools to do just that. The better news is that this article will show you some practical examples on how to use those tools.