Use the Dup Key in Subfiles

Published: September 2, 2009

Hey, Ted:

I hope you don't mind another question about the "old" stuff. How do I program for the Dup key in a data entry subfile?

--David

This is a good technique to know, David, and it's not hard to do.

Let's start with a simple subfile of 10 records per page. There are three input fields: a date; a customer number; and an amount. Here's the DDS:

A                                      DSPSIZ(24 80 *DS3)
A                                      INDARA
A          R SFL                       SFL
A            SDATE          6S 0I  8  6DUP(31)
A            SCUST          8A  I  8 16DUP(32)
A            SAMOUNT        7Y 3I  8 30DUP(33)
A          R CTL                       SFLCTL(SFL)
A                                      SFLSIZ(12)
A                                      SFLPAG(12)
A                                      CF03(03)
A  22                                  SFLDSP
A  21                                  SFLDSPCTL
A N21N22                               SFLINZ
A                                  7  6' Date   Customer    Amount'
A                                      DSPATR(UL) 

Notice the DUP keyword on each of the entry fields. DUP tells which indicator to turn on when the DUP key is pressed.

And here's what the subfile looks like:

Date     Customer        Amount
010203    AAA           44______
*******   BBB           45______
*******   ********      ********
*******   CCC           55______
010204    ********      66______

The asterisks show where the dup key was used.

In your program, which I'll illustrate with RPG, you'll need three save fields for the three duplicable fields. In my program, I cleverly begin the names of these save fields with the word Save.

Here's the idea: When you retrieve a record from the subfile, test the dup key indicators. If a dup key indicator is on, copy the save field to the entry field. If a dup key indicator is off, copy the entry field to the save field.

Here's my code that illustrates the process:

Fqad2561d  cf   e             workstn sfile(sfl:rrn)
F                                     indds(DspfInd)

D rrn             s              4s 0

D DspfInd         ds
D  ExitRequested                 1n   overlay(DspfInd:  3)
D  WriteCtl                      1n   overlay(DspfInd: 21)
D  WriteSfl                      1n   overlay(DspfInd: 22)
D  DupDate                       1n   overlay(DspfInd: 31)
D  DupCust                       1n   overlay(DspfInd: 32)
D  DupAmount                     1n   overlay(DspfInd: 33)

D SaveDate        s                   like(SDate)
D SaveCust        s                   like(SCust)
D SaveAmount      s                   like(SAmount)

 /free
     *inlr = *on;

     dow '1';  
        // clear the subfile
        WriteCtl = *off;
        WriteSfl = *off;
        write ctl;
        // present the subfile
        WriteCtl = *on;
        WriteSfl = *on;
        exfmt ctl;
        if ExitRequested;
           leave;
        endif;
        for rrn = 1 to 10;
           chain rrn sfl;
           if DupDate;
              SDate = SaveDate;
           else;
              SaveDate = SDate;
           endif;
           if DupCust;
              SCust = SaveCust;
           else;
              SaveCust = SCust;
           endif;
           if DupAmount;
              SAmount = SaveAmount;
           else;
              SaveAmount = SAmount;
           endif;
           // do something here with the data
           // from the subfile record
        endfor;
     enddo;
     return;
 /end-free

Maybe other readers will write in with more dup-key ideas.

--Ted

                     Post this story to del.icio.us
               Post this story to Digg
    Post this story to Slashdot