• Guru: How Do You Do That With RDi? Part 3: Complex Compiles

  June 19, 2017 Susan Gantner

  In an earlier tip I tried to convince RDi users to give up compiling in PDM because the RDi compile interface has the time-saving Error List to offer. I offered some tips that help me with my compiles in RDi. Here I’ll continue my “Compile in RDi” campaign by offering some additional ideas for those who have more complex compile processes.

  There are two common issues I hear that keep people returning to PDM for their compiles. One is that their library lists aren’t set up correctly for the compile and the other is that they need to do something …

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• Guru: Error Handling in SQL PL, Part 1

  June 12, 2017 Ted Holt

  I once fancied myself a logical thinker. I changed my mind when I started programming computers. I quickly realized that I was incapable of writing an error-free program. Chalk up another valuable lesson to experience. More experience taught me to program for both expected and unexpected conditions, and now I apply that concept to all languages that I use, including SQL PL.

  SQL PL has excellent exception-handling methods, and they’re not hard to use. In this article and Part 2 to follow, we look at how DB2 informs you that your SQL request worked correctly or not. Next, we’ll take …

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• Guru: How To Cancel A Bad SQL Update

  May 15, 2017 Ted Holt

  In Three Ways To Manage Unmatched Data I wrote about the use of the RAISE_ERROR function to force a SELECT statement to cancel when unmatched data is considered a fatal error. Another good use of RAISE_ERROR is to force an UPDATE statement to cancel when an invalid condition occurs.

  To illustrate, imagine that you and I work in a factory. All factories have inventory. The people we serve purchase some inventory items and manufacture others. Our job is to write a program that will allow certain people to zero out the inventory balance for certain types of purchased items.

  The …

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• Replacing Source in The Twenty-First Century

  October 18, 2016 Ted Holt

  In Searching Source in The Twenty-First Century, I introduced the use of regular expressions for searching within a source member. Searching is great, but sometimes you need to replace what the system finds with something else. Here’s how to replace text when using regular expressions. Let’s begin with a source member. Notice that there are nine constants named Stat10 through Stat90. Let’s replace Stat with Status_. Obviously we can’t replace Stat with Status everywhere it’s found. That would be disastrous! Instead, let’s use a regular expression to find the instances where Stat is followed by a digit. I

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• Handling Constraints Revisited

  March 31, 2015 Paul Tuohy

  I recently had an email from Doug, who was making use of some code I had published way back in February 2010 in my article Handling Constraint Violations in RPG. The article discussed how to trap a constraint violation caused by a WRITE/UPDATE/DELETE operation and, more importantly, how to determine the name of the constraint that caused the violation. Doug had come up with an instance where my code was not working! After going through the usual stages of denial, anger, and some expensive therapy, I read the rest of the email. Doug’s code worked fine with an RPG

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• Handling Constraint Violations in RPG

  February 17, 2010 Paul Tuohy

  Constraints have been around for a long time but have not quite made it into every programmer’s tool kit. This is partly explained by the fact that implementing constraints in an existing application can be tricky–but it doesn’t explain why constraints are not used extensively in new applications. On a side note, the lack of constraints on a database is one of the reasons I have heard why data should be moved/copied from the i to other database servers, such as SQL server and Oracle, for such things as data warehousing. To a “pure database person,” a lack of constraints

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