SETLL,SETGT *START, *END, *HIVAL, and *LOVAL

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Let's go through how SETLL and SETGT interact with special constants like *START, *END, *HIVAL, and *LOVAL in RPGLE for navigating files.

These special constants help you position the file pointer when you don’t know the exact key value, and want to move to either the start or end of the file.

🔁 SETLL vs SETGT

Operation Meaning
SETLL Position to record equal to or greater than the key
SETGT Position to record strictly greater than the key

🔰 Special Constants

Constant Meaning
*START Lowest key — positions before the first record
*LOVAL Lowest possible value for the key (same as *START)
*END Highest key — positions after the last record
*HIVAL Highest possible value for the key (same as *END)

✅ Examples

1️⃣ Read File Forward from the Beginning

Setll *Start MyFile;
Read MyFile;

Dow Not %EOF(MyFile);
   Dsply MyFileField;
   Read MyFile;
EndDo;

  • Reads all records from beginning to end.

2️⃣ Read File Backward from the End

Setll *End MyFile;
Readp MyFile;

Dow Not %EOF(MyFile);
   Dsply MyFileField;
   Readp MyFile;
EndDo;

  • Starts at the end and reads in reverse order.

3️⃣ Use *LOVAL and *HIVAL for Keyed Files

For a keyed file where you want to read:

All records ascending:

Setll *LOVAL MyKeyedFile;
Read MyKeyedFile;

All records descending:

Setll *HIVAL MyKeyedFile;
Readp MyKeyedFile;

🚫 When NOT to Use

  • Don’t use these constants with non-keyed files or files opened with OPNQRYF.

  • These are not valid as actual key values, just file pointer positioners.

Perfect — here's a real-world example showing how to use SETLL *HIVAL with READPE to get the last record for each key value, such as the latest invoice per customer.

🧾 Scenario

You have a file called INVOICESL1, logically keyed as:

CustomerID (Ascending)
InvoiceDate (Descending)

This way, the most recent invoice appears first for each customer when reading backward.

📄 RPGLE Example: Get Last Invoice Per Customer

Dcl-F InvoicesL1 Usage(*Input) Keyed;

Dcl-S CustomerID Char(10);
Dcl-S InvoiceID  Char(10);
Dcl-S InvDate    Date;

CustomerID = 'C123';

Setll CustomerID InvoicesL1;
Readpe CustomerID InvoicesL1;

Dow Not %EOF(InvoicesL1) and CustomerID = 'C123';
   Dsply ('Invoice: ' + InvoiceID + ' on ' + %Char(InvDate));
   Readpe CustomerID InvoicesL1;
EndDo;

🔍 Key Points:

  • Logical File Sort Order is crucial: must be CustomerID ASC, InvoiceDate DESC.

  • SETLL *HIVAL + READPE starts from the end of the file.

  • The program keeps track of the previous CustomerID to avoid processing multiple invoices per customer.

 

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