• Guru: Common Table Expressions Can Replace Query Chains

  June 5, 2017 Ted Holt

  Modernization efforts often concentrate on the database and programs. That is well and good, but there is more to modernization. Replacing Query for IBM i with more modern query tools is also important. But what do you do with those queries that people depend on? More confusing, what do you do with query chains?

  A query chain is a series of queries that run one after another, consolidating and reformatting data in temporary physical files, in order to produce a resulting data set, often in report form. It’s not unusual to see small CL programs like the following one:

  PGM
  

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• Guru: Confessions Of A Recovering RDi Outline Addict

  May 22, 2017 Susan Gantner

  As an unabashed RDi fan, my list of “favorite features” is pretty long, but right up near the top of the list has always been the Outline view for RPG IV. It was Outline that finally got me to move to WDSC (RDi’s predecessor) from its predecessor, CODE (a.k.a., CODE/400) many years ago.

  I’ve long been amazed at the number of RDi users who say they don’t use Outline – some don’t even have it in their RSE perspective any more. I have always suspected that’s because they closed it by accident long ago and never had a chance to …

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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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