QMF Z Client with Procedures and REXX Logic

Introduction

Mainframes remain the backbone of enterprise data management. With IBM's Query Management Facility (QMF) Z Client, business users and developers can create queries, reports, and batch jobs on z/OS.

But did you know that QMF can do much more than just queries?
One of its most powerful features is the ability to create Procedures with Logic - combining QMF commands with REXX scripting to build intelligent, automated workflows.

In this blog, we'll explore how this works, why it matters, and walk through a practical example.

What Are Procedures with Logic?

• Standard QMF Procedures
  Normally, a procedure in QMF is just a list of QMF commands (RUN QUERY, SAVE DATA, EXPORT, etc.) executed in sequence.
• Procedures with Logic
  When you add REXX programming statements to your procedure, you can:
• Add conditional execution (e.g., run only on Mondays).
• Include loops, variables, and error handling.
• Dynamically interact with QMF global variables.
• Build mini-applications that automate reporting and data export.

This hybrid capability makes QMF more than a reporting tool-it becomes a programmable BI environment.

How It Works

1. Start with a REXX script
   Every procedure with logic begins like this:
2. /* REXX */
3. Switch to QMF Command Environment
   Use:
4. ADDRESS QRW

This tells REXX that the following commands are QMF commands.

5. Mix QMF + REXX
• QMF commands go in quotes ("RUN QUERY MYQUERY").
• REXX code (like loops, conditionals) runs outside quotes.

Example 1: Hello World with QMF

/* REXX */

SAY "Hello! This is a QMF + REXX procedure."

ADDRESS QRW

"RUN QUERY SALESQ"

SAY "Query completed."

Here, QMF runs a query called SALESQ, while REXX provides messages to the user.

Example 2: Weekly Report (Only on Mondays)

This example shows conditional logic: only run the report if it's Monday.

/* REXX */

ADDRESS QRW

if date('W') = 'Monday' then

   do

     "RUN PROC WEEKLY_SALES"

     SAY "Weekly report generated!"

   end

else

   do

     SAY "Sorry, reports only run on Mondays."

   end

exit 0

error:

exit 8

This script prevents accidental report runs on the wrong day, reducing workload on Db2.

Example 3: Export with Dynamic Variables

You can even pass variables between REXX and QMF global variables:

/* REXX */

salesRegion = 'APAC'

ADDRESS QRW

"SET GLOBAL (REGION="salesRegion")"

"RUN QUERY REGION_SALES"

"EXPORT TABLE SALES_DATA TO 'APAC_WEEKLY'"

The value of salesRegion is sent into a QMF global variable, driving the query dynamically.

 Why Use Procedures with Logic?

• Automation → No need for manual steps; procedures run unattended.
• Consistency → Standardized, repeatable workflows across teams.
• Error handling → Exit codes (exit 0, exit 8) and REXX error signals improve reliability.
• Flexibility → Mix business rules and data logic in one place.

This feature turns QMF into more than just a reporting tool-it becomes a data automation framework for z/OS.

 Practical Use Cases

• Scheduled Reports → Generate and export weekly/monthly reports without user intervention.
• Data Quality Checks → Run queries and automatically alert if anomalies are found.
• Conditional Exports → Export data only if certain thresholds are exceeded.
• Interactive Applications → Use SAY and PULL in REXX to interact with users at runtime.

Conclusion

Procedures with Logic in QMF Z Client allow organizations to blend the power of SQL and QMF commands with the flexibility of REXX scripting.
This is a perfect example of how modern mainframe tools combine classic reliability with programmable intelligence.

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Shashank Sonavane
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