19
Tue, Nov
1 New Articles

TechTip: Enhanced Debug Experience for SQL Routines in IBM i

SQL
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

New enhancements simplify the debug of SQL routines.

 

IBM first improved the debugging of SQL stored procedures, functions, and triggers way back in the V5R2 release when it introduced the *SOURCE debug view. This debug view allowed IBM i developers to debug their original SQL source code instead of having to debug the ugly C code that DB2 for i generates behind the scenes for SQL routines.

 

While the *SOURCE debug view greatly simplified things for developers, there were a couple of issues with this support that slowed down developers. First, the Step command often worked differently than with traditional IBM i programs. The Step command would have to be requested multiple times for a single SQL statement because it often takes multiple lines of C code to implement a single SQL request. Second, the EVAL command could not directly reference SQL variables; the variable name always needed to be qualified with a label (e.g., EVAL mylabel.VAR1).

 

The good news is that the recent Technology Refreshes for the IBM i 7.1 and 7.2 releases have finally eliminated these debug headaches for SQL routines. The following SQL stored procedure example will be used to help you better understand these recent enhancements.

 

CREATE PROCEDURE debug_test(IN p1 INT, OUT p2 INT)

LANGUAGE SQL

SET OPTION DBGVIEW=*SOURCE

BEGIN

 

DECLARE v1 INT;

 

SET v1 = (SELECT COUNT(*) FROM projects);

 

IF v1 > p1 THEN

   SET p2 = 0;

ELSE

   SET p2 = 100;

END IF;

END

 

Let's assume that you've set and hit a breakpoint on the first SET statement using the IBM i graphical debugger as shown in Figure 1. Prior to the recent enhancements, a developer would have had to hit the Step Over menu bar task 11 times to execute the SET statement and advance to the next SQL statement. The green-screen debugger, STRDBG, had the same issue when using the Step command or F10 key.

 

Obviously, this strange Step behavior frustrated and confused many IBM i developers. That inefficiency and confusion all goes away with the latest enhancements; a single Step request will now advance the debug session from the SET statement to the IF statement!

 

120514MilliganFig1

Figure 1: You've set and hit a breakpoint.

 

The other issue arose when trying to determine the current value of a variable in a procedure. A developer could not simply type EVAL V1 to examine the current value of this local variable. Instead, the variable name had to be qualified by a label. That limitation was an even bigger headache with this example routine because a user-defined label wasn't specified on the BEGIN clause. A developer would first have to dig through the generated C code to find the system-generated label before executing the EVAL command. For this example, the generated label is SQLP_L2, so determining the current value of V1 required this "simple" command:

 

EVAL SQLP_L2.V1

 

Clearly, the old EVAL support was cumbersome. With the recent enhancements, a developer just needs to enter EVAL %%V1. This improvement eliminates the need for a developer to create, find, or enter a label-name! (If you're already in the practice of adding labels and using those labels in the EVAL command, that approach will still work.)

 

Accessing these enhancements for the green-screen debugger is as simple as loading the Database Group PTF level 32 for the 7.1 release and level 3 for the 7.2 release. These enhancements for the graphical debugger are being delivered with the next IBM i Access for Windows service pack, which is scheduled to be available in December 2014.

 

If you weren't aware of the no-charge IBM i graphical debugger available for debugging SQL routines (and IBM i programs), check out this white paper for more information.

 

So get your systems current and enjoy debugging your SQL routines without the headaches!

Kent Milligan
Kent Milligan is a Senior Db2 for i Consultant in the IBM Lab Services Power Systems Delivery Practice.  Kent has over 25 years of experience as a Db2 for IBM i consultant and developer working out of the IBM Rochester lab. Prior to re-joining the DB2 for i Lab Services practice in 2020, Kent spent 5 years working on healthcare solutions powered by IBM Watson technologies. Kent is a sought-after speaker and author on Db2 for i & SQL topics.
BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  • SB Profound WC 5536 Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application. You can find Part 1 here. In Part 2 of our free Node.js Webinar Series, Brian May teaches you the different tooling options available for writing code, debugging, and using Git for version control. Brian will briefly discuss the different tools available, and demonstrate his preferred setup for Node development on IBM i or any platform. Attend this webinar to learn:

  • SB Profound WP 5539More than ever, there is a demand for IT to deliver innovation. Your IBM i has been an essential part of your business operations for years. However, your organization may struggle to maintain the current system and implement new projects. The thousands of customers we've worked with and surveyed state that expectations regarding the digital footprint and vision of the company are not aligned with the current IT environment.

  • SB HelpSystems ROBOT Generic IBM announced the E1080 servers using the latest Power10 processor in September 2021. The most powerful processor from IBM to date, Power10 is designed to handle the demands of doing business in today’s high-tech atmosphere, including running cloud applications, supporting big data, and managing AI workloads. But what does Power10 mean for your data center? In this recorded webinar, IBMers Dan Sundt and Dylan Boday join IBM Power Champion Tom Huntington for a discussion on why Power10 technology is the right strategic investment if you run IBM i, AIX, or Linux. In this action-packed hour, Tom will share trends from the IBM i and AIX user communities while Dan and Dylan dive into the tech specs for key hardware, including:

  • Magic MarkTRY the one package that solves all your document design and printing challenges on all your platforms. Produce bar code labels, electronic forms, ad hoc reports, and RFID tags – without programming! MarkMagic is the only document design and print solution that combines report writing, WYSIWYG label and forms design, and conditional printing in one integrated product. Make sure your data survives when catastrophe hits. Request your trial now!  Request Now.

  • SB HelpSystems ROBOT GenericForms of ransomware has been around for over 30 years, and with more and more organizations suffering attacks each year, it continues to endure. What has made ransomware such a durable threat and what is the best way to combat it? In order to prevent ransomware, organizations must first understand how it works.

  • SB HelpSystems ROBOT GenericIT security is a top priority for businesses around the world, but most IBM i pros don’t know where to begin—and most cybersecurity experts don’t know IBM i. In this session, Robin Tatam explores the business impact of lax IBM i security, the top vulnerabilities putting IBM i at risk, and the steps you can take to protect your organization. If you’re looking to avoid unexpected downtime or corrupted data, you don’t want to miss this session.

  • SB HelpSystems ROBOT GenericCan you trust all of your users all of the time? A typical end user receives 16 malicious emails each month, but only 17 percent of these phishing campaigns are reported to IT. Once an attack is underway, most organizations won’t discover the breach until six months later. A staggering amount of damage can occur in that time. Despite these risks, 93 percent of organizations are leaving their IBM i systems vulnerable to cybercrime. In this on-demand webinar, IBM i security experts Robin Tatam and Sandi Moore will reveal:

  • FORTRA Disaster protection is vital to every business. Yet, it often consists of patched together procedures that are prone to error. From automatic backups to data encryption to media management, Robot automates the routine (yet often complex) tasks of iSeries backup and recovery, saving you time and money and making the process safer and more reliable. Automate your backups with the Robot Backup and Recovery Solution. Key features include:

  • FORTRAManaging messages on your IBM i can be more than a full-time job if you have to do it manually. Messages need a response and resources must be monitored—often over multiple systems and across platforms. How can you be sure you won’t miss important system events? Automate your message center with the Robot Message Management Solution. Key features include:

  • FORTRAThe thought of printing, distributing, and storing iSeries reports manually may reduce you to tears. Paper and labor costs associated with report generation can spiral out of control. Mountains of paper threaten to swamp your files. Robot automates report bursting, distribution, bundling, and archiving, and offers secure, selective online report viewing. Manage your reports with the Robot Report Management Solution. Key features include:

  • FORTRAFor over 30 years, Robot has been a leader in systems management for IBM i. With batch job creation and scheduling at its core, the Robot Job Scheduling Solution reduces the opportunity for human error and helps you maintain service levels, automating even the biggest, most complex runbooks. Manage your job schedule with the Robot Job Scheduling Solution. Key features include:

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • LANSAWhen it comes to creating your business applications, there are hundreds of coding platforms and programming languages to choose from. These options range from very complex traditional programming languages to Low-Code platforms where sometimes no traditional coding experience is needed. Download our whitepaper, The Power of Writing Code in a Low-Code Solution, and:

  • LANSASupply Chain is becoming increasingly complex and unpredictable. From raw materials for manufacturing to food supply chains, the journey from source to production to delivery to consumers is marred with inefficiencies, manual processes, shortages, recalls, counterfeits, and scandals. In this webinar, we discuss how:

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • Profound Logic Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application.

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: